Can you characterize the deterioration more specifically? I only ask because every time I run this exercise for myself I end up back on macOS, despite any hiccups.
An example of deterioration:
Jeff Goldblum's 30 second "Presenting three easy steps to the internet" https://www.youtube.com/watch?v=rjY0xsoozs8
And now when you want to set up a fresh Mac it's a parade of dialogue boxes:
Do you want to turn on Siri? No. (the dialogue-choice is probably "maybe later" ugh)
Do you want to share app analytics with developers? Yes.
Do you want to add Touch ID? No, because I'm setting this up for someone else.
There are more!
I gave those examples -- each of which having a different answer or reason -- to show that the problem of onboarding is nontrivial, but Apple has spent no(?) effort toward fixing it. It's the same for new iPhones and iPads.
NB I don't know if you sign into your Apple account it pre-answers these questions. That'd be nice.
Not OP, but I have been using an M1 pro Mac Book since release. It's not sluggish in any way whatsoever.
If you have not tried it this is an absolute game changer for Mac users moving to Linux. https://github.com/RedBearAK/toshy
I've been running it for 3 years now. I am so macpilled that I had to install it on my new Framework 13 pro.
The Mac muscle memory was always my biggest hurdle with Linux. I always felt handicapped by it. But Toshy eliminates that.
Not OP, but a decades-long Mac user. Removing CLI tools over the years would be one way, though I run Homebrew and have everything I want or need. That doesn't change that scripting is less useful on a fleet of devices.
Also, the UI has been in decline for a decade or so, with the regrettable decisions under Alan Dye. Thankfully, Zuck poached him and we're all grateful for that. I mean, what they've done to our icons is tragic, the glyphs in the menus was intern-level boneheaded, and reduction of contrast to "get out of the way" of our content has made everything less usable, especially for people with vision issues.
A bug that I filed about window-ordering when using the Cmd-` / Shift-Cmd-` shortcuts has been live since 2010 without getting fixed, though an industrious HN user posted a link to the background utility they made to fix it themselves[0].
0: https://github.com/tacomanator/sash