nVidia decided to redouble their efforts, and now they might still crash occasionally, but are largely way better at driver stability and they brought CUDA into the world at the same time.

AMD decided that shitty software didn't seem to stop them from selling GPUs, and also we're too busy desperately surviving a decade of Intel anti-competitive practices that nearly killed the company, and bet everything on Ryzen. They also worked to make pretty good physical GPU hardware. Meanwhile, their GPUs still couldn't run Blender as fast as a similarly specced nVidia card because their OpenCL implementation was god awful. They ran at literally half the render speed of a similar nVidia GPU. It was stuck on OpenCL 1.x the whole time, because the 2.x implementation was literally broken. They nearly didn't have ANY hardware render solution for an update to the Blender rendering engine in 3.x because OpenCL 1.x literally couldn't do what they wanted, and ROCm is a joke. AMD engineers helped put together an emergency/late breaking fix to create an HIP implementation, and that works, at least mostly.

My pet theory is that not only does AMD not give a fuck about software, but they saw how nVidia was struggling with market segmentation from consumer cards being effective compute cards, and didn't want to run into those same struggles if they had a real CUDA competitor. Instead, they got to rub nVidia's face into the dirt with their GPUs that had way more VRAM, and not worry that it would chew into their professional GPU profit margins, because you can't compute on consumer cards. Oh, I forgot to mention, the whole time this nonsense is going on, AMD is pushing really hard to get their professional GPUs into Supercomputer clusters, and has several premier supercomputer implementations where their GPUs have no problem being used for top level compute tasks, almost like they CAN actually write GPU compute software and just don't give it to consumers.