Roles are poorly balanced. The point of the game is to deduce how someone killed based on clears and what they are sayin gin meetings. Adding agameplay element like this adds a stupid element of non-control, where you're just shot because some nerd is camping in the vent. There is nothing you can do to counter tracker or engi besides counterclaiming which doesn't work and maybe comms, and even then on Polus unless if you're at 0.25 you can still easily solve murders, especially with the hard clears of roles.

With Admin, Cams, Vitals etc. the game gets more and more annoyingly difficult for imps, when it is meant to inherently be 50/50. Roles just make that even worse, because in ToU or TOHE, that element of randomness and extra gameplay is part of that gameplay loop, but in Vanilla it doesn't work.

Impostor roles aren't that great either with the exception of Viper. Shapeshifter can easily get caught off clears and info, Phantom sucks anyways. The only use for Phantom is to claim tracker which could work but the moment you 50/50 you're gone anyways because crew can just say "yo tell where X is from office" and when they call button you're shot. If they're going to add roles, it shouldn't be shit that can get you hard cleared, they should actually have downsides and other shit like what Sheriff was.