TLDR: The entire GPUArrays.jl test suite now passes with AMDGPU.jl. There are still some missing features and it is not as mature as the nvidia version, but this space is progressing rapidly, and benefited from the generic GPU compilation pipeline that was initially built for CUDA.jl
The problem with AMD GPGPU is not software, it is that AMD literally does not care.
Rocm gets releases every few months or so. The llvm project part is mirrored to GitHub in real time.
I think AMD has some work to do on non-C++/Python ecosystem engagement for sure, but they've built a foundation that's quite easy to build upon and get excellent performance and functionality; AMDGPU.jl is a testament to that.