Apparently from 2022 onwards the pi 4 and pi 5 support vulkan.
I only ever tried a simple godot 3.x 3D scene exported to a radxa zero using compatibility renderer. 1 character, some cubes, some displaced terrain.
It runs fine at 720p or 360p.
Don’t expect to ship your final 3D scenes without some serious compromises, the chips on these things are usually on the 10 to 80 GFLOPs range, that’s 1/4th the performance of an xbox 360 at best.