Wayland does not support screen savers: it does not have any provision that allows screen savers to even exist in any meaningful way. If you value screen savers, that’s kind of a problem.
Adding screen savers to Wayland is not simply a matter of “port the XScreenSaver daemon”, because under the Wayland model, screen blanking and locking should not be a third-party user-space app; much of the logic must be embedded into the display manager itself. This is a good thing! It is a better model than what we have under X11.
But that means that accomplishing that task means not just writing code, but engaging with whatever passes for a standards body or design committee in the Wayland world, and that is… how shall I put this… not something that I personally feel highly motivated to do.
Equivalent mechanisms exist in Wayland, but XScreenSaver doesn’t have logic to interact with them. This can be solved by either teaching XScreenSaver how to talk to these new mechanisms (difficult as it was developed for X from the ground up) or implementing something new.