There's a lot of trash talking of x86 here but I feel like it's not x86 or Intel/AMD that are the problem for the simple reason that Chromebooks exist. If you've ever used a Chromebook with the Linux VM turned on, they can basically run everything you can run in Linux, don't get hot unless you actually run something demanding, have very good idle power usage, and actually sleep properly. All this while running on the same i5 that would overheat and fail to sleep in Windows / default Linux distros. This means that it is very much possible to have an x86 get similar runtimes and heat output as an M Series Mac, you just need two things:

- A properly written firmware. All Chromebooks are required to use Coreboot and have very strict requirements on the quality of the implementation set by Google. Windows laptops don't have that and very often have very annoying firmware problems, even in the best cases like Thinkpads and Frameworks. Even on samples from those good brands, just the s0ix self-tester has personally given me glaring failures in basic firmware capabilities.

- A properly tuned kernel and OS. ChromeOS is Gentoo under the hood and every core service is afaik recompiled for the CPU architecture with as many optimisations enabled. I'm pretty sure that the kernel is also tweaked for battery life and desktop usage. Default installations of popular distros will struggle to support this because they come pre-compiled and they need to support devices other than ultrabooks.

Unfortunately, it seems like Google is abandoning the project altogether, seeing as they're dropping Steam support and merging ChromeOS into Android. I wish they'd instead make another Pixelbook, work with Adobe and other professional software companies to make their software compatible with Proton + Wine, and we'd have a real competitor to the M1 Macbook Air, which nothing outside of Apple can match still.