Things are turning around for AMD. If you have an AMD card, go to pytorch.org, click Linux+ROCm and install PyTorch. 3 years ago, this was hopeless. Today, most mainline things work. I ran nanochat on MI300X and it just worked. I think that's true about MI350X now too. The MI350X machine is stable.
They are clearly behind NVIDIA, nobody doubts that. And a lot of investment into software will be required to catch up, ecosystem, compiler, and driver. But 2 years ago they seemed hopeless, now they don't. Things take time. HipKittens is a great codebase to study to see where AMD's LLVM backend is still lacking; compare it to the CUDA Kittens.
For training, it's NVIDIA and Google in first. AMD in second. And nobody in third. Intel and Tenstorrent are not remotely close. Huawei examples segfaulted. Groq gave up selling chips. Cerebras isn't available anywhere. Trainium had a 5 day wait time to get one instance and I lost interest.