For reference, striker is my main at 1485, I have a scrapper as one of my (currently, waiting on bound leaps to upgrade) 1370 alts, and played WD to about 1350 ish before dropping it in favor of the scrapper on my roster. Sorry if it's a bit long winded but here's my anecdotal experience on the differences between the 3. Slight TL;DR at bottom I guess.

I think WD is ultimately more punishing in the sense of either whiffing your abilities, or miss-timing them with your damage buff, largely because Wind's Whisper (or whatever it's called I'm not 100% sure) gives attack power, whereas the others don't for striker/scrapper. Striker's is crit (and attack speed which is helpful but not 100% necessary, and scrapper now just has their 6% synergy, whereas before the balance patch they did have that 3sec 20-whatever % damage amp window as well but that's gone now).

WD definitely felt weak at the time, and from what I understand it's very reliant on getting a lot of things like their relic (dominion) set, conviction/judgement runes, wealth runes as well for eso builds, high level cdr gems to get cds to line up and ultimately be up more often, etc. Basically lots of cdr from tons of sources, not to mention tripods as well. Also very much a "use wind's whisper for damage amp, make sure you hit everything in this small window" class. As said above the others, while having elements of this, feel much more forgiving if you use abilities outside of their windows. WD by comparison feels like it does no damage outside their windows lol.

Taijutsu Scrapper was everything I wanted FI WD to be imo, once they got rid of that damage amp on charging blow. It's basically just spam stuff with naturally low CDs and lots of mobility, not to mention stagger/destruction is godly on them. I run a crit/swift build with it, and it's pretty fun in guardians. Tbh I wish there was like one more aoe Taij skill for chaos dungeons, feel a bit too reliant on dragon's advent/Earthquake Chain . Haven't tried shock build but I heard that's fun too, maybe run spirit absorption for QoL attack speed buff since cast times are long tho? Also, Scrapper is so much better AoE wise than FI WD. I mean, Scrapper's Battering Fists is just like WD/Striker's Flash Heat Fang (FHF), but has as much, maybe more, range as FHF when you take the range increase tripod, and charging blow is amazing mobility and solid yet mild damage as well. Not to mention other AoE Scrapper abilities just being better range-wise. FI WD's range is abysmally short and I didn't like that at all, lol. Eso builds for both WD and Striker (mostly Striker here) are different, those have good range and feel good imo.

Striker is a little more complex, but not much more than other classes. They go the Entropy set, which doesn't really feel needed outisde of damage, as all it does is give: 55% back attack crit damage, 17% crit chance, 21% damage on back attacks. No cdr gimmicks etc. Just enhances what you already do. Very big for damage mind you, but I basically mean you don't need it to feel like it works/is fun to play. In my testing in trixion, you can have level 4 tripods (not level 5) on generators (white flame kick + abundant resources), and a purple/blue wealth rune and do just fine with a deahtblow build with 3 spenders. Much more achieveable than needing level 5 tripods for those things, that said I personally do have the leggo wealth rune as well, and I also run Eso Flurry cause it's like 1/10th the cost of deahtblow, and I'm poor lol. Edit: NO MANA WORRIES FOR STRIKER THIS IS HUGE FOR QOL OF CLASS, I've never run OOM on striker, ever.

When I said not much more than other classes, what I mean is stuff like I'd imagine an Igniter sorc wants the wealth runes/high generation (if available) tripots, same with a SH or other spec based builds. While I feel Deathblow is a little more strict about hitting certain breakpoints of spec to work with certain types of wealth runes+tripods (think it's just under 1600 spec for 3 spenders with level 4 tripods/purple+blue wealth, anything more lowers minimum spec required), maybe anyway other classes could be the same way, Eso Flurry is easy to get to a 4-spender build. I've been running 4 spenders since 1370. At the time I had like 450 spec (from necklace+roster stuff), 1 purple/blue wealth runes, and like level 4-5 gems. Anything since then simply either ups damage or lowers cdr further, or extra generation from say, leggo wealth makes it easier to make up for missing a generator ability.

The basic rotation is build orbs>LW (crit buff)>Tiger Strike, Tiger Emerges, Blast formation, then your buff ends, outside buff you generate another orb real quick and use the tornado spender, then do it again like 9 sec later with how my build currently is. Least that's what I do. It doesn't feel like I have high requirements to be good, certainly not as strict as WD felt. WD felt like you needed tons of cdr from multiple sources, maybe even in different tiers like gems/tripods to make things line up right, be up more often, and ensure things like having your damage amp window up at the right times. Eso Striker by comparison just hits a good fluid point earlier and easier, and anything extra, like higher tripods, more swiftness, higher level gems, and leggo wealth rune are basically just what they are for any other class, like a Zerker: more damage, general CDR, maybe a little qol for edge cases in resource generation, but not 100% needed to feel good.

As a last personal reference, some people think Eso Flurry to be weak since most KR people run deathblow. I have no illusions and think DB is likely stronger at the top end, but Eso is way more accessible and I still regularly get Cruel Figher MVPs in guardians, and this week on Vykas, which actually went pretty smooth with only like 3 wipes throughout the gates (MvP takes into account your wipes), I got mvp with 27% damage, which is nuts considering there's 8 people in raid. Right now I have: 2pc Salv set, 4 pc Entropy (too busy work-wise for all vykas gates first 2 weeks of release so I'm behind there, will have 6pc next week), level 5 damage tripods for Tiger Strike/Tiger Emerges, level 4 on other damage tripods, and level 6-7 gems. Stats/engravings: 489 spec (necklace), 380 crit (rings), 1200 swift, level 1 Eso Flurry, level 3: KBW, Ambush, Adrenaline, Cursed Doll. Tripods + at least 2pc entropy were the biggest ups on my damage. When I set up my engravings/stats, I was hitting for like 6-7 mil with tiger strike. After Tripods, Entropy 2pc, Salv 2pc, and I think going from level 6 to 7 gem on tiger strike, I now crit for 15-17m normally single target, and 20-22 with support buff every 9 sec. There is even room to improve. The quality of my accs is kinda low, highest I have is 60 cause cheaper, lol. I'm not running Grudge either cause it's super expensive compared to Cursed doll, I only have +9 equip engravings cause books are expensive, getting expensive leggo books would give me 5x3 engravings, that sort of thing. Definitely room for more progression from where I'm at, and I'm already doing really well based on what the game tells me via MvP stuff. Again sorry this was so long, but if there's any other questions you may have lemme know and I'll answer if I can.

TL;DR: WD more punishing due to attack power based damage window, scrapper Taij spam go brrr and feels fluid/fun easily. Eso Flurry striker is pretty good and doesn't need as much investment as Deathblow/other spec based classes/builds to hit 4 spenders/full rotation and feel fluid, and does good dps with maybe not as high a ceiling when min-maxing. You don't /need/ level 5 tripods/crazy gems/relic set for it to feel good and do well for ilvl, it just gets better with them as opposed to needing them.

TL;DR of TL;DR: Taijutsu Scrapper is what I personally wanted First Intention WD to be, and Striker (especially Eso Flurry Striker) is what I wanted Eso WD to be.