There are browser extensions that automatically switch from YouTube to an alternative platform if video is available on both.

Watch on Odysee Firefox LINK

PeerTube Companion
Firefox LINK

It is difficult to switch to custom roms when manufacturers like Samsung block bootloader unlocking or like Xiaomi make the process hard.

https://github.com/melontini/bootloader-unlock-wall-of-shame

If you want to run Android apps on Linux try Waydroid. It is probably one of the best option right now.

Samsung is a joke company. They block oem unlock from One ui 8. Samsung IMS isn’t working in custom roms (AOSP) because they have some close implementation of IMS.
You should look to other company for next phone.

Can’t you get WhatsApp to work in Waydroid?

List of linux phones OS: https://linmob.net/resources/#smartphones Sailfish os suported devices https://docs.sailfishos.org/Support/Supported_Devices/