EU should double down with a regulation stipulating that people are free to install whatever OS they want on devices (smartphones included) and companies can't gatekeep it.
the problem is firmware. the community has been porting postmarketos to android phones for years, there are a ton of phones where PmOS will boot but most things like camera, phone service or bluetooth won't work because they are missing the firmware necessary.
It'd be one hell of a battle considering companies would probably just pull a Microsoft and release the specifications as horrendously as possibly so no one can use them but their army of devs