Also I would not trust on the current US administration to keep deals that limit US corporations in force forever.
I have used secure boot to secure Linux systems, so it is useful for Linux users. But the danger that oligopolists will misuse it is not unreal.
Never say never, but I just don't see how the option for one to boot an alternative OS on the vast majority of commodity hardware is going to be rolled back any time in the foreseeable future.