What does your `top` say? What does your browser's performance tool (e.g. `about:performance`) say?
I went from a constantly-overheated Linux laptop to a completely calm Linux laptop, on the same hardware, distro, and DE. Checking for unnecessary processes that eat CPU, spurious ACPI events, overly-heavyweight browser tabs goes a long way. Making sure the browser uses hardware support to play YouTube is another heavyweight.
It takes some time, but much less time than I had expected.
So the Mac has battery saving built in to the OS. You are doing a lot of reverse engineering to achieve something other software/hardware does automatically.
And to be specific, I suffer from bad hardware/software communication. On a linux laptop, no less (System76, which I would never recommend). Linux S3 sleep is not hardware sleep, I lose a lot of battery there. WiFi and Bluetooth connectivity either has to be battery draining or have poor performance.
The battery my laptop has itself is also too small, and could only get moderately good life if it had an optimized OS anyway. Again, a Linux-first laptop.
I am sure if I switched to a Lenovo with a big battery that I would be better off than I am now, so I'm also complaining a bit about my hardware. But the problem is still there.
With Apple M2 paired with an OS designed for it, with high end batteries and screens, I don't see any pairing of (laptop) hardware and software competing, on a fundamental level. Every other system is second class.
Edit: ACPI events is the key word here, and it is not worth anyone's time to wade through that garbage to get sane laptop performance. The ACPI stuff isn't even designed for end users to alter, and it is hacked together due to all the hardware variations out there. It is simply doing the best job it can, on average.
There's kind of an implicit lie when people say linux works on laptops at all. It works on MOST laptop configurations in MOST functions. But it BARELY works in others. You find this once you dig sufficiently deep enough.
I run the OS of my choice on hardware of my choice in a way of my choice (that is, not Debian, Ubuntu, or Fedora). The small amount of tweaking I have to do to get the experience tailored for me personally is completely worth it, besides other, less tangible benefits like "free as in freedom".
If I were fine with someone else making all these decisions for me, because making them myself is more painful than accepting someone else's not entirely comfortable decision, I'd go for an Apple device, no doubt.
Tweaking the OS to play nicely with particular hardware is key. Apple are very good at it. I suppose e.g. System 76 also tweak Pop OS to run especially smoothly on their hardware. Linux is very much ready for that: when I worked at Google (2011-15), I had a Linux laptop with a Google's internal variety of Ubuntu, adapted to a relatively few hardware models they used as desktops and laptops. It worked basically flawlessly, and my T420 had like 6 hours of battery runtime browsing and coding. All I had to customize was the GTK theme and such.
Maybe something like "tweak packs" that adapt Linux to some very specific widespread hardware could be a hit.
I went from a constantly-overheated Linux laptop to a completely calm Linux laptop, on the same hardware, distro, and DE. Checking for unnecessary processes that eat CPU, spurious ACPI events, overly-heavyweight browser tabs goes a long way. Making sure the browser uses hardware support to play YouTube is another heavyweight.
It takes some time, but much less time than I had expected.