No, Twitter is no dying no matter how much Elon Musk makes a fool of himself. Controversy is good and he's pretty good at stirring controversy around him.

Initially the payed checkmark will open up a small stream of revenue for social media companies - Twitter, Facebook/Instagram, etc, later it will be used for identity verification - first by paying a sum, which can be traced back to a bank account and later by uploading official documents or linking to some government service.

Twitter or Meta could be identity providers and get actual money for providing this service for other platforms. I can see Twitter & Meta being the providers for the "internet passport" in the future. Bleak, but possible and lucrative.