Nvidia's software support remains "best in class" so they've become the default for a lot of this stuff. To overcome that I think you'd have to get a lot of hobbyists and by extension interested young people using your hardware instead of Nvidia. So you'd have to have good software support, decent hardware, and low hardware cost. People started with Nvidia because most machines had an Nvidia card in them, and Nvidia's software support was carried-over momentum from how they've supported their GPUs with PC gaming. I've tried AMD, for example, and the compatibility matrices and bugs and just general lacking software support for ML on their hardware makes it a total non-starter. It may be a lot better with current-generation stuff but it's going to take a lot for me to trust AMD for ML.