At this point you're actively contributing to the death of free speech if you're still active on X in any way. There are no excuses to use it still if you have any sort of functional moral compass.
Usually, posting on Twitter or quitting it has a very tiny, almost imperceptible effect on the larger world and it's certainly not something to get worked up about.
For example, keeping a Twitter account in case someone wants to contact you seems pretty harmless.
But I think it's bad for your mental health to lose perspective about it. It all adds up, but it's 99.999% other people doing the adding, and unless you're in the right position to use leverage, you are mostly an observer of national and global events.
This means that morally, you don't need to feel responsible for big stuff like that - unless you see a way to end up in a position where you have that kind of leverage.
Using big, negative events as justification to scold random nearby individuals is mostly just making your local community more unpleasant.
Example: I do encourage people to vote, but I'm not going to worry about one voter more or less.