Linux is close to being capable of full-time duty rather than just an interesting experiment. I run it on old obsolete Macs long abandoned by Apple. Performance is excellent (I'm running right now with Linux Mint 21 on a Mac Pro 5,1 from 2012).
Integration with my iStuff is better than I expected, in some cases better than macOS. An example: Mom texted me a document that she wanted me to print. Plugged the phone in the mac to transfer it...and...Apple provides no way to get it. Or at least no way while the internet was down even when directly connected by cable. Rebooted into linux --- and the iphone shows up in their file browser, all I had to do is navigate to it and copy it. easy-peasy.
Some parts that still need to be fixed/improved:
Upgrades: there really is no way to upgrade to a new version of the OS. Mint has a tool to do so, but it doesn't work. You have to uninstall/downgrade everything in the system until it matches the configuration it expects, then the upgrade will likely produce a non-working system anyway. It is quicker and more reliable to do a fresh reinstall on a different drive or partition and then reinstall all your apps, since you will have to do it anyway.
Fragility: Updates sometimes breaks the system to the point that it no longer boots. ALWAYS do a backup before updating. Recovery from a broken update can be frustrating.
grub: grub is the default bootloader. It is also terrible, fragile, and is frequently corrupted which means it won't boot. There are repair tools, but they don't work all the time (my batting average is .000). Fortunately this is easily fixed by installing refind.