Twitter may become a total hellscape and it wouldn't matter.
Why? Because apart from politics Twitter (which is indeed beyond dangerous), there are gazillions other niche/sport/hobby Twitters that don't care for the dumpsterfire around them.
As for organisations and brands, it's all the analytics and ads and promotional tweets that makes them be there. Otherwise they wouldn't even bother having a presence.
If you take all journos, politics, current affairs and the like, Twitter may look half sane. And that's the crux. A very chunky majority doesn't care or see what the politics side looks like.