Don’t they all have mostly the same data, with a small / negligible delta between each other?

I'd argue that data in this case is more like the actual models they use, their codebase and their engineering talent. Not deep enough in the sauce to say one way or another how big the realistic delta between companies is though.

Maybe so. That leaves just the hardware. Deprecates badly. Maybe gamers will take it off their hands gladly?

I would be delighted to see a glut of compute. I'm not optimistic, though.

contracted revenue streams and subscriptions are also assets. Having first claim on those has tangible value.