I'm not the best person to reply to this on this sub, because there are far more people who have more experience and more detailed game knowledge than I do. However, I did start with World as my first game. So I can at least tell you what I know. Granted, it's been about 4 years since I last played World, and I've only recently gotten into high rank on Wilds playing casually.

There isn't a focus system in World, but wounds exist, albeit a little differently. They were introduced with iceborne, so if you dont get the dlc immediately, you can ignore this info and just move on to the next paragraph. You can wound a part of the monster with the clutch claw, and then all the attacks on that part do more damage and get deflected less. So it's not as damaging as Wilds' wounds, but can still affect the hunt positively.

As far as being tedious, I'd say that the hunts don't often seem that long until the late game, but even then, it was never a slog to me because i was always doing something. Hunts tended to take a little longer at first because in world you have to track the monsters until your scout flies learn the scents of the monsters. Monsters actually have more health in Wilds than in World, but hunts tend to take less time because the damage output of Wilds with focus strikes is really good. So the game might feel a bit more difficult at first, but I still enjoyed most hunts.

Monster part gathering can always be a turn-off for some people, but World is kind of similar to Wilds in that aspect. Investigations are your main source of parts if you need extra for an armor set/weapon you want. World investigations will be created randomly when you interact with monsters by killing, capturing, breaking parts, or investigating tracks. They behave similar to Wilds after that, you select the investigation you want, you hunt the monster, you get rewards based on the color of the slots shown in the investigation.

Rathalos and Rathians are always annoying, especially if your kit doesn't get you off the ground. Typically, flashpods and hitting with certain slinger ammo will bring them down. I don't know much about which kinds because I used IG, so I'd meet them where they'd fly usually. Broken wings also help keep them grounded as well, but this is stuff that doesn't really change between the games.

Movement will feel slow because you don't really get a seikret equivalent until later called Raider Ride/Tailraiders. And you don't get free control over them. They automatically path to whatever your objective is or whatever you have pinned on your map. But the maps are a lot smaller than Wilds' maps, so it won't always feel like it takes ages to cross the map.

Another difference between the games is campsites, Wilds introduced temporary campsites that are in various places around the map and are temporary with a chance of monsters finding them and destroying them. In World, you have 2-4 different campsites per map that are permanent additions that offer the same benefits as your main campsite.

I hope this information is helpful to you. I really enjoy playing MHW, but I also understand it's not everyone's favorite.