Kroko

Adb command line interface is a major barrier for most users. Even with GUI tools built on top of ADB that still a barrier for many users.

I don't have experience with linux os on phones. You should ask https://www.reddit.com/user/Mister_Magister/. He is community developer of sailfish os https://www.reddit.com/r/linux/comments/1mzla4h/ive_been_daily_driving_and_developing_mobile/

They aren't made in eu.

goodram make stuff in Poland.

https://www.goodram.com/en/categories/consumer/

Waydroid support MicroG

You can install app from Android Debug Bridge (adb). It will bypass all new restriction.

List of all Linux phones https://linmob.net/resources/#smartphones
Next gen Jolla Phone https://forum.sailfishos.org/t/next-gen-jolla-phone/23882

There are phones supporting Linux https://linmob.net/resources/#smartphones

https://xdaforums.com/t/bootloader-unlocking-option-removed-from-one-ui-8-0.4751904/post-90249798

One UI 8 will block oem unlock and relock bootloader in all Samsung.

True, the README needs some updates. Feel free to open issues or make pull requests.

You can't unlock samsung in canada/usa models. There are paid services but it isn't worth it. Nobody makes custom roms for locked devices.