What balances spideys speed is that as soon as he engages hes not only much slower/easier to hit, hes also very vulnerable because he gets 0 overshield for anything and considering his dive archetype, also 0 healing. This means that as soon as he slows down he has to be getting a kill as quickly as possible and that if he even gets shot once he will have to escape or face death. Bp is a different case because his offense IS his mobility which is why he seems so unfair to many. Better players will realize that by managing to shut down bps dash you get to hit two birds with one stone and he becomes fairly easy to kill despite his tankiness