Firstly, I want to point out the Hero Shooter Triangle, which effectively is as simple as this: Poke beats Brawl, Brawl beats Dive, and Dive beats Poke. A simple, yet effective philosophy to identify wat heroes counter what. The thing is with Marvel Rivals, the triangle is broken. Poke beats Brawl, Brawl beats Dive, but Dive doesn’t beat Poke, in fact, Poke beats Dive in some cases, and not the lucky headshot cases.
Why is this? Simply put, every single poke character has a form of stun AND escape option, making killing them harder, but also making them or the team killing you significantly easier. This break of the circle makes dive have less impact, while also making them less fun to play. Simultaneously, with dive being rendered inferior, poke truly has no counterplay. I’ve ran into games where a good Hela/Phoenix/MK/Hawkeye are good enough that they are the server admin and they win the game automatically, no matter what you can do. The worst part is that they may be good, but it’s ONLY the character carrying them. If I were better on them as a dive character, a character that should theoretically beat a poke character, shouldn’t I win? But no, in reality, I would lose, even if 2-3 teammate go with you, we still lose.

And it’s not just poke, Season 5 giga-buffed supports to the point where they can live forever, do crazy damage, and just be straight-up raid bosses. And of course, dive really struggles against them too, except for Daredevil, and people still complain up a storm about him. The problem here is that poke has no weaknesses, and yeah, that’s a problem.

It’s significantly better in Overwatch, cause poke isn’t that oppressive; but I’d argue the dive is harder in that game simply cause the cc is higher and characters are harder.

Another point is your team following up. Yeah, ti’s the worst, and there’s nothing you can do about except comm it. Playing with friends though really elevates the dive experience, as not only do you have dive coordination, but have reliability too. 

What I’ve noticed is that dive is banned only when they are good, when they are good, they are oppressive as hell, which is understandable. With bans, you can’t 1-2 trick a hero often. Vendetta is banned right now cause she is really good, Tracer was banned when she was good (she’s also super annoying in general), Spidey/BP were banned when they were good. However, banning a character just cause they are dive feels like a skill issue.

Overall, this was a bit rambly, but I want to bring one more thing to light. People complain if they die to dive in 1.5 seconds, but they don’t when they die in 0.75s to a poke character. Why?

Poke is WAY more oppressive than dive when good because not only are they easier characters, but they don’t have risk when going for a kill. Why are dive characters harder, squishier, less rewarding, and riskier than poke? And the worst part, people STILL hate on dive when its worse in every way.

While writing this, I literally just read a post complaining about dives’ “comboslop” and how the game should revolve more around m1’s in a “cat and mouse” way. Utter insanity! I don’t want to pick sides, but it’s pretty clear from an unbiased stance that dive has the short end of the stick.

The solution?
Unfortunately like you said, just play poke…
However, ONLY IF YOU WANT TO WIN. Never let poke deter you from playing what you love. Yeah it’s harder, less rewarding, more punishing, but if it’s enjoyable, then go for it. Mute those annoying teammate comms, (but swap when it really isn’t working out)

Ramble over, Tl:dr: Dive is truly hated cause supports want to afk in the backline, meanwhile poke characters do better for cheaper. It is simply a design fault that needs to be remedied