Udon is cumbersome, needs a lot of technical knowledge to operate, and obtaining prefabs like cyantrigger is difficult and out of the way, especially for people in non-english speaking parts if the world.
On top of that, Udon is notoriously slow and malperformant, being a large impactor on many peoples' frames in the game.
We need essentially what we had in SDK2, a simplified, albeit limiting, world creation system that uses native unity functions and things that run through internal C# for optimization.
Needing to emulate udon simply to make a chill world that has some mirror toggles and a videoplayer is a ridiculous waste of resources. Especially if the creator wants said world to be very visually detailed.