I am confused. Are you asking for alternative to Plank for Budgie or Gnome users?
Most Gnome users are using extension which doesn't work for Budgie (because Budgie is not Gnome, and vice versa). Extension like dash-to-dock, dock-from-dash, dash-to-panel. For Budgie, as @SethStorm666 said you can just modify the panel to look like a dock. AFAIK there is no dock program like Plank (Even Lattedock for Plasma is dead too now).
brent So....I know firsthand Wayland will not run Plank. The terminal clearly tells you "Wayland can't run plank."
That is incorrect. This is the real error log:
❯ plank
[CRITICAL 15:09:14.423788] [AbstractMain:255] Only X11 environments are supported.
I think you look at it the wrong way. It is not Wayland cannot run Plank, it is the other way around. Wayland (or X11) is the highway and Plank is the vehicle. The new highway only allows vehicle with 4 wheels, unfortunately you ride a Harley Davidson motorcycle. It is a very nice motorcycle but it only has two wheels. Either you stay on the old road, or just switch to riding a car so you can use the new road. It is your choice, just beware that the old road might get bulldozed any day to construct new apartment. (I am going too far with this analogy).
Plank may be able to run on wayland, but it looks like the project is unmaintained. So far nobody is interested in forking and improving it to support wayland.