As a Quest standalone user, you are able to buy avatars that aren't Quest/Android compatible off the avatar marketplace. This should probably be prevented or at least give some WAY better indicators!

Already had one user on the VRChat Discord server's Community Support forum say they did this without realizing it wasn't compatible.

I opened up VRChat on my Android phone, and immediately was able to find an avatar on the Avatar Marketplace that isn't Quest/Android compatible.