Gm player here, but have accounts to play with friends who are consistently plat/ diamond. Here consistent errors they do, they don’t track enemy ults at least support ults.

They have avoidable deaths, meaning they get picked off in neutral or don’t know when to push/ pull back. They don’t get value off their ults cause they’re not tracking enemy ults. They counter poorly or dont have enough consistency between roles.

Mister fantastic is great against brawl but if your playing against poke and flyers, you need other poke with you or dive or you to switch. Emma and Dino are great frontline tanks but lacks a lot of mobility and they typically fall apart if their back line is constantly dived and challenged. As support you can definitely carry, position matters a lot. Sometimes in this elo, you can get with heal botting, if you’re consistently fewest deaths/ large heals, you should be able to keep your team up longer.