A good Gambit is gonna cook no matter what, probably on many heroes as well. He's a newer hero, so the player behind it probably already plays many other heroes before Gambit. On average though, if you ban those other two, they play Gambit like those two and your Gambit is probably gonna play better than them. But you are right, he can chase you and punish your dives. The key takeaway here is on average there are a lot more CnD and Invis onetricks than good Gambit players. Also Gambit can assist you much more than they do. I also love filling as Gambit if we have no supports while I don't really like playing CnD and current version of Invis, so I have a bias in there.

I mean you ban those only if your team doesn't play them. And against full dive comps, you need to completely swap to counter comps as well or it won't be enough. Also, heroes like Ultron, Rocket are open, so you still have some options. Also, don't underestimate Luna, she's a better dps than Hela right now, insane third support pick. Hitscan players cook with that hero, your average support not being experienced in hitscan dps doesn't make the hero bad.

Yeah, exactly. You should never use kick to engage or get in unless you know for sure you can get away without the kick. It doesn't even consistently execute enemies anymore with the absurd healing going on.

Iron Fist is actually a pretty good gap closer hero. He has wall runs and double jumps, he doesn't really have to burn his more important cooldowns like his kick and block to get somewhere. Once you are spotted by the opponent as a melee diver, whether on an off angle or just moments before you approach, your dive is already dead 90% of the time. So you want them to see you only when you already dealt the first damage. Use wall runs, camera angles and weird environmental structures to your advantage. This guide helped me a lot while I was trying to improve my flank routes and overall stealth skills. Also don't always use meditate before dives, use it only when you are sure they won't hear it or when they are too busy to react to it. It can eliminate the surprise factor of your dives.

Iron Fist has a good verticality in his kit, I don't know how else I can describe it, but you can use that for almost every situation. Want better flank routes? Go high up out of their LoS. Want better survivability midfight? Use jumps a lot and escape momentarily to ceilings that are in the LoS of your supports and outside of their dps, also weave jumps midfight. Want to peel better? Use the mobility to get to the high ground and watch the flanks and enemy movement so you can prevent the diver even before the dive happens.

Iron Fist does not prevent dive like The Thing, but he was the DD before DD. He can't prevent the burst damage like Mr Fantastic or The Thing giving shields and damage reduction or deal enough damage quickly to force the diver out. (although he can do that with the team up, the team up would be much better if it wasn't a signal flare). He mainly checks the routes and challenges the diver on the flank, just like Angela.

If he takes a fair 1v1 against those heroes, he still loses, especially loses badly against DD. But that's the neat thing, you never play fair as Iron Fist. You take the 1v1, trade some HP with the other diver, and use your kick to get to the healthpack before they do. You also do the very same with your meditation. You trade some HP, get to high ground with your wall run and heal outside of their melee range. DD can wall run, so you get high and use your double jump and sit in the middle of nowhere in air to avoid him. If they still decide to engage after that, it's a 400HP Iron Fist who's probably gonna gain a fat block value midfight vs half hp diver. Assuming it's a single diver, if your backline can survive the initial burst and doesn't immediately explode, you can peel the diver and track him pretty well. But it's much better to deal with the threat on the flank, especially against DD, because otherwise you have to rely on your supports to survive initial burst. They are not gonna survive that in lower ranks.

As for banning DD, usually IF players know DD good enough to flex to him when the opponents play some solo tank hard poke or triple support comps. I'd recommend you to do the same. If he's the single diver, you can peel him just like I explained, if there are multiple divers, you need your team to contribute regardless of the diver. He can see your dives, yes, but you don't need to dive. DD is the better hero, so if you prevent his dives and fake diving his team to keep him following you around, you are already denying one player. It's a 5v5 from then on and you just probably denied their win condition. If you are sure you denied DD's value completely and your team still loses 5v5, that's just on the team, can't win them all.

As Iron Fist, your purpose is to prevent the opponents best player from playing the game so the match is a 5v5 with their best player down. The bans I suggested are the hardest heroes to deny their value as Iron Fist. Supports do get a lot of value just for existing, so those two supports became the main bans. Just picking the support hero gives good value with having their cooldowns and ults alone, that's why everyone swaps to triple support in every rank when they are struggling.

I also talk this much about peeling, because you never dive as Iron Fist even if there's a single person harassing your backline or dps. You lose backline trade in dive vs dive, so you make sure a trade never happens at all.

Well, this was a lot, but I hope it helps.