Axios Plank likely relies on certain X11-only APIs to identify windows and applications (such as a window's XID) in order to group running applications to launchers, and to group windows from the same application together. Switching that over to a Wayland solution is the easy part.
The hard or impossible part is knowing when to show and hide the dock. I assume that most people want the dock hidden when they have an application open, and only show when the mouse is near the bottom of the screen. On Wayland, applications (specifically, windows; the Plank dock is, for all technical purposes, a window) do not have that information on Wayland, by design. They would have to use private protocols with every single compositor so the compositor can tell Plank when to show and hide. On the compositor developer side, that is a bunch of extra work for a 3rd party application, and I highly doubt there would be buy-in to do it.
Reasons like that are why (almost) every dock application has stopped development in favor of using built-in solutions from the desktop environments.
