I tried to make a quest compatible avatar, but for some reason it says it uploaded but I can't use it on Quest.

[pluhskiki]

Also is there any way to make a Quest avatar compatible but somewhat good quality?

[Hallucinatory]

It needs to be optimized more, it failed the performance checks for android. You can check this by looking for an X on the top right or in the avatar details it should tell you.

As for quality, there's only so much you can do for a quest compatible avatar.

Optimization includes:
Combining meshes
Atlasing your textures
Compressing your textures
Getting rid of extra bones by rewriting mesh data if you're adding clothing in Unity by using VRCFury's Armature Link component
Using tools like PolyTool or optimize your meshes in Blender
Using VRCFury's Blendshape Optimizer component
Lowering particle count