What did it take to port Linux to M1 series Macs (which at least has an unlocked bootloader)?

How do I install GNU/Linux distribution on a latest Galaxy S25 or iPhone or Google Pixel or Apple Watch or... (these are likely top-selling general compute devices in the world)?

Yes, on Windows PCs, Linux usually works better than Windows itself (except for the very newest stuff for a short while). But I think you missed the point of the GP.