They are not playing god. They own a platform, they are determining who can and cannot speak on that platform. That's the same thing every news paper, internet forum, email server, BBS, public bulletin board, or really any publishing of any kind has done since the invention of publishing.
Twitter is not part of the government, and it does not have a monopoly on internet communication. Hell, it doesn't even charge for its services. You are not entitled to use their platform.
If you are disgusted and disappointed in social media for their behavior, that's perfectly reasonable! There are things you can do about it! you can refuse to use their service, refuse to recommend it to friends, promote competitors, etc.
What you cannot do is pretend that just because they are a large wealthy organization you have some kind of right to use their platform to say whatever you want.
There's the obvious case if they should discriminate against users based on a protected class.
Platforms have also been sued for things like tortuous interference and deceptive practices as a consequence of deplatforming users.
If a user engages in activity that is either clearly illegal or contrary to clear and sensible Terms of Service, removing them is obviously a fine and good thing.
Outside of those circumstances though, I would not take it as a given that there is no recourse if a user is deplatformed.