Can anybody with a deep knowledge of the AI space, explain to me what's the real moat of CUDA ?

It's clear to everybody that it's not the hardware but the software - which is the CUDA ecosystem.

I've played a bit in the past with ML, but at the level of understanding I had - training some models, tweaking things, I was using higher level libraries and as far as I know, it's pretty much an if statement in those libraries to decide which backend use.

So let's suppose Intel and others does manage to implement a viable competitor - am I wrong in thinking that the transitions for many users would be seamless ? That's probably not the case for researchers and people pushing the boundaries, but for most companies, my understanding is there would be not a lot of migration costs involved ?