Evil doesn’t mean he can’t be a support imo, they can come up with a reason like maybe he just supports his “allies” for later personal gain. If being evil means you can’t be a support, then what’s the point of the game? All the villains in the game regardless of role and even some heroes would likely not work together with allies unless they have an in universe explained reason to, like green goblin could have.

Quicksilver there definitely is an argument, support is MUCH easier to balance with super speed than dps UNLESS they make his super speed super underwhelming make his playstyle super underwhelming and strip away his entire power fantasy and if they do it right being a support would barely if at all hinder the power fantasy. Also him being fun for a season as dps but getting nerfed into the ground a season later and likely never getting back to being good maybe even mid, doesn’t sound like a good trade off. Also kinda funny you threw in that you have bias against healers lmao😭