I get what you're saying. I agree with it. But I think there are valid reasons why individuals and larger organisations would retain a presence on the site. Some global organisations work in countries where they could lose links with a lot of their followers (some of whom really need the access) if they just quit, and not all followers in all countries would have the option to follow them to other platforms, plus there is a value to retaining the widest possible audience.

Another reason - you might (as an individual or a group) take the view that fighting from within gives you a stronger position than leaving and what was once a great platform just sink into the mire.

I'm not particularly advocating for any of these, but they are valid positions to take.

My own position is less easy to justify. I still have a twitter account, but never use it other than an occasional remote "share to Twitter/X" and I do occasionally get information from some of the Twitter accounts that publish useful stats in certain areas. I'm still there mainly from inertia. Also, I wonder if the current owner will be selling up soon - given that anyone who steps into a govt job in the US can sell their business and avoid paying any something-or-other tax, thus saving millions. It might soon be back in sane hands.