Imagine if NVIDIA had been able to buy ARM. That could be a threat in a couple directions.
Though perhaps the opposite direction is more interesting and what you were getting at: what if the off the shelf arm cores had NVIDIA’s engineering behind it.
If they pulled that off, that Nvidia would have been very powerful. CUDA + ARM + leading node would have put them in a similar position that Intel had with x86 back in the day.
The competition would have struggled there - nobody has CUDA equivalent, only AMD has GPU equivalent, nobody has install base of software like ARM. RISC-V (or intel) even executing super fast would have been years away from being competitive across the board like this.
It might have also wrecked AMD, since the weak point of their GPU strategy is reliance on x86. If Nvidia+ARM came on strong, that'd weaken x86's stranglehold on PCs, which would ultimately weaken AMD since they don't have a leading position in other markets to fall back on.
Nvidia would have a lock on mobile devices, the increasingly AI-based datacenters, as well as some degree of PC side including gamers. Microsoft would pick up on the software side and we'd have Winvidia instead of Wintel.
> The main concern among regulators was that Nvidia, after the transaction, would have the ability and incentives to restrict access to its rivals to Arm´s technology, which would eventually lead to higher prices, less choice and reduced innovation. [2]
[1]: https://www.ftc.gov/legal-library/browse/cases-proceedings/2...
[2]: https://www.pymnts.com/news/regulation/2022/collapse-of-nvid...
That wouldn't work since many companies already had been licensing the ARM architecture, not just cores.