ARM architecture doesn’t matter much, implementation does. Apple Silicon is not fast and power efficient because it’s ARM, but because Apple is ahead of the chip-designing game and spares no expenses when it comes to build fast CPUs.
I think its a bit of both - x86 has a complex instruction set and a huge backward-compatibility albatross around its neck, so in comparable x86 and ARM implementations, ARM is likely to be simpler (or have more room to add optimisations).
ARM was dominating the mobile market long before Apple Silicon - or even the iPhone - came along, partly through power efficiency, partly because x86's only unassailable advantage was software compatibility - which isn't such an advantage on a mobile device that just isn't physically suited to running PC software. Even before iOS/Android there were things like EPOC/Symbian with roots in ARM.
The other unique thing about ARM is that competing chip makers can license the tech on a "pick'n'mix" basis - which is why Apple were able to make their own tailored chips with the ARM instruction set - so there are lots of independent players like Apple, Qualcomm, Amazon, Ampere, NVIDIA etc. working on ARM whereas x86 is basically "Coke or Pepsi" - er, sorry, Intel or AMD.
So x86 doesn't just have to stay ahead of Apple, it has to beat all of the other players in the ARM business. Apple don't really have a dog in the high-performance computing or server race (as that's a tiny fraction of their market that they can afford to lose) but NVIDIA and Amazon certainly do - and, like the mobile market, the days of servers/HPC being dependent on running Windows are coming to an end with Linux taking a huge share - Linux has supported ARM for years and Linux/Unix developers have a culture of writing portable code.
I think there may be a couple of reasons why Microsoft aren't falling over themselves to support bare-metal ARM Windows on Mac (apart from the fact that it would
not be the trivial job it was with x86 Boot Camp). First is that, right now, an M2 running native Windows would probably leave a Surface X choking on its dust. Yay for Apple, but a problem for Microsoft who's Windows business model still relies heavily on licensing it to OEMs, and while OEMs can build Qualcomm-based WoA PCs, they won't be able to make M2 based PCs... embarrassing for MS.
Second - MS rely heavily on Windows' backwards compatibility to keep their Windows business going. Apple was able to "smooth" the x86 to ARM transition by being pretty ruthless about dropping support for older software (including
completely axing 32 bit support) - MS probably can't afford to do that - either by decree, or by offering a really enticing and powerful WoA option that might encourage people to re-tool (like a 16" MBP or a Mac Studio running WoA natively). I think at this stage MS are hedging their bets by just having the Surface X as a just-about-credible tablet alternative that is of little interest to most Windows users.
I think we're long past "peak x86" and "peak Windows" (once you look beyond traditional PCs) but "Wintel" was so dominant in the 90s/00s it won't be going away quickly. Long term, though, I think they'll fade into irrelevance as most software becomes processor independent, and only the writers of operating systems, language runtimes and web browsers have to worry about processor architecture. We're not there
yet but it isn't far off.