If a deck lets you win on turn 1 6.25% of the time, and completely flop over 50% of the time, you’ll lose often enough that your deck isn’t going to win any tournaments. That’s not an oppressive force in a metagame.
But if even that is too much for certain players, they can just avoid Vintage. There are non-eternal formats with no t1 wins. Pioneer, Standard etc have no such t1 wins.