what’s the difference in practice
On the other hand, essentially every ML project works out-the-box with nvidia GPUs. There's still vendor lock-in to nvidia, but it's more palatable.
If you spend $100k of an ML engineer's time to get FooNet to work on TPU, then the cutting edge advances or you pivot and instead you need BarNet support - you might wish you'd spent that $100k just buying a stack of nvidia GPUs.
Also the hyperscalers as per usual are far more expensive than others - this is an incomplete list https://getdeploying.com/reference/cloud-gpu/nvidia-h100 - GCP seems to be around the $100/hour for the 8xH100 config (similar to AWS).
They aren't the incumbent; this would be an incredibly short-term strategy, wouldn't it?