In my opinion, enshittification occurs when, among other things, the user experience is "ruined" in order to generate profits by offering "improvements" that are nothing more than going back to previous states of the platform, only now paying or paying more.

While it could happen that some parts of the Fediverse could become Shitty, it seems impossible to me that it would happen in the whole fediverse. There's always the option of blocking problematic instances and such. And anyway, users who enter the fediverse do so mostly fleeing from enshittification, so, I think, we are less willing to put up with that kind of bullshit and will leave sooner rather than later, maybe creating something new (and better, if possible).