Progress is fundamentally limited not by finances (which are a human abstraction) but by the energy budget and how much can be extracted from it. This has always been the case, really, although it's unusually blunt in case of AI since compute mostly needs cheap power.

There's a separate question of who controls how much energy, and can therefore decide where it's spent. This isn't an inherent limitation to progress, though - it's an imaginary limitation that exists in our minds, a collective delusion, if you will. There's no law of physics that says Sam Altman gets to decide; we as a society choose to respect the property rights that translate to his economic (and attendant political) power to do so. We could choose to stop respecting them, and if we do so collectively, there's nothing they can do about it.