Been there, done that. At the begin of 2022, I sold /everything/. iPhone XR, Apple Watch 6, MacBook Pro. All gone. Since then I have lived with Android and Windows mainly. Why not linux? It's accessibility for visually impaired is, frankly, dogshit - and I only see on one eye and that barely so...

Anyway; transfering from iCloud to the other devices was a bit of work, but also not impossible. You can download your stuff from iCloud via their WebUI or by installing the Windows tools - this gives you the opportunity to have it download just about everything to your drive, originals included, which you can then migrate to something else. In my case, I migrated to Photoprism. Not a great replacement, but good enough.

As much as I have grown a disdain for Apple, their system *does* work... mostly. And it's so frustrating that the only closely similar alternatives are from Google. Argh. Chosing between two illnesses...

That said, it IS possible, I DID the transistion and now I have a working setup. But... Expect to invest time, if you ever do. 2-3 days, roughly.