Given the outcry after the last attempt at a sale and the fact that nVidia got blocked (a US company) who would risk buying arm at the moment given that multiple competition watchdogs are currently paying attention.
They're preparing to IPO in 2023. It's a shame the Nvidia sale didn't go through, now they'll likely die a slow death because they don't have enough R&D resources to compete with the big boys who are just going to design their own CPUs instead of buying the design.
Small ARM Cortex's have taken over the microcontroller market. Billions made each year from every large microcontroller manufacturer. They aren't going anywhere. It's hard to believe ARM wouldn't make enough from licensing fees and from each one sold to make an easy profit. Maybe the license doesn't account for individual sales, IDK?
New secure ARM Cortex's are launching everywhere too, so they are very much alive and well, for the next 20 years minimum.
I dunno if Cortex-M chips will be better for long, though. Some of the RISC-V specifications like interrupt controllers need a bit more time, but they have very good support in mainline compilers like the GNU toolchain.
My experience writing C for RISC-V MCUs is about the same as doing so for Cortex-M platforms. They're a bit low-volume/expensive atm, but the core is very appealing to chip makers because it has solid software support and no royalties.
I also wouldn't write ARM off, though. Their 'coming-soon' MCU neural accelerators could open a lot of doors if it works well on a low power budget.
That seems to be said of a lot of things that do end up disappearing. Hard to tell whether there are real roots in the market or if it's going to evaporate like so many other things.
The "big boys" you mentioned are all holders of ARM Architectural Licenses - there are only 15 of them in total and they likely pay a shitload of money for the privilege [1].
And they will need to hold on to the ARM architecture and thus the license payments for quite the time... I bet Apple could go and develop a completely new ISA from scratch, but that would mean a third infrastructure switch in two decades on the PC and the first one on everything mobile - a lot of work for everyone involved with no real benefit, and especially after they spent multiple billions on getting their ARM stuff to the performance (in compute power and power efficiency) point they need.
Even the "biggest boys" aka nation states fail at making decent alternatives to the x86/64 and ARM duopoly - the Russian Elbrus and Indian SHAKTI CPUs are utter exotics and Chinese Loongson are a plain fork of MIPS (and again, completely exotic).
The Apple M1 lineup, for example. The M1 standard, pro, max, and ultra are not differentiated by their ARM cores other than the quantity of them. It's really the GPU cores and media encoding components. And that Neural Engine thing is really important for many apps and OS features. At what point do the general purpose CPU cores on a modern chip become minor players that have very little impact on overall chip performance? I don't think we're there yet, but it certainly could happen.
EDIT - I'm saying M1 vs M1 Pro vs M1 Max vs M1 Ultra. Not M1 vs Intel i7
That not really true though. M1 had considerable better single core performance at the time of release than anything else with a comparable TDP. And the Neural Engine is only useful is fairly narrow use cases.
I wonder if there were similar conversations about math coprocessors when they joined the CPU. What did people say about increasing specialization of cores then? The closest recent analogue is GPUs joining the CPU on mobile devices, but it was only recently that those weren't complete garbage.
Would either of those things genuinely put other companies off? If I were looking to expand into that market then it wouldn't put me off. They're manageable hurdles to purchasing rather than reasons that buying ARM would be bad business.