phaolo: If ARM will manage to replace x86 for PCs (in 10-20 years?), I'm worried about videogame preservation.
Even with a perfect Rosetta in a new Windows ARM, we'll probably end up missing old abandoned features required by games.
Perhaps we'll need both emulation and virtual machines for win7-10 x86-64 at that point..
Considering how well e.g. Amiga (and various other old systems, including gaming consoles even up to PS2 and Nintendo N64 and GameCube) work nowadays, I am not concerned that much. I can nowadays play pretty much any Amiga or PSX or PS2 game just fine, even though the system where I play them has no hardware compatibility with the old systems in any way. (Apparently those aforementioned emulators work fine even on a lowly ARM-based Raspberry Pi 3 and 4; I haven't tried them yet.)
It depends how well Intel and AMD keeps up. If they become stuck in the technological curve in the long run, then it is natural the ecosystems move to more efficient (and powerful?) solutions, just like Apple is doing now, and MS has dabbled with ARM-based Windows machines as well. We'll see, maybe Intel and AMD break the jackpot with some new tech... Heck, who knows, maybe even Intel or AMD itself would at some point introduce some M1-like design, either based on ARM or RISC-V or something else? A totally different architecture that merely "emulates" x86?
Somehow I am more interested in RISC-V than ARM as RISC-V is "open source CPU design", ie. anyone could start making their own RISC-V CPUs, no need for licensing etc. That somehow sits into "free PC" idea quite well; not that the current situation with AMD and Intel competing neck to neck is that bad either, or AMD vs NVidia vs Intel GPUs. As long as there is real competition also on the hardware side.
https://www.theregister.com/2020/03/09/risc_v_intel_amd_arm/
All I hope that some kind of relatively free and open computing ecosystem persists, the reason I prefer PCs over e.g. Apples or gaming consoles. Something that lets you decide what to install and from what sources, even alternative operating systems. I don't care if it has x86 or ARM or RISC-V or whatever. At the moment I am not that concerned because luckily there seems to be some demand for such open ecosystems, and there are already non-x86 PC alternatives too, Raspberry Pi being one (even if it is a low-performance one at this point). There are no restrictions what OS I may use with RPi, not even UEFI SecureBoot requiring some digital signature by Microsoft before I am allowed to run an alternative OS on my PC...