I just started playing Overwatch 2 not too long ago, I’ve played as most of the characters. Also though playing against the characters I got some insight as to what adjustments should be made.
Ana - Ana should be able to lay down and shoot. This could also alter her abilities (like the grenade becomes a hitscan shot) and/or give her a roll instead of a jump while laying down (which would bring Ana back to standing upright).
Doomfist - Climb walls and/or radar. Might add to the skill ceiling but also lessen the requirement for playing.
Echo - 360 melee perhaps a longer cooldown with added range…
Symmetra - Using Symmetras teleporter should instant reload your weapon, 5 different individuals per teleporter.
Orisa - 1 player can now ride on the back of Orisa. Just kidding (not really).
Zenyatta - Zenyatta should be able to fly during his Ultimate. Probably suggested before but, yeah.
I don’t think these suggestions are overpowered at all. In fact, they may be a little underwhelming but nevertheless can contribute to game winning plays.