For a Mac Mini with external storage that may be passable, but for a laptop like the MacBook that’s pretty much a no go.
This move by Apple should not be confused with generic UEFI secure boot with user-loadable keys, which yes, IMO is a good thing for most people.
Apple however has locked down the hardware in a way which only benefits them.
This move is actually what everyone feared Microsoft would do with UEFI (which they didn’t) and literally caused endless FUD and uproar on the Internet (and it’s still going on).
Now that Apple is actually doing it nobody bats an eye, because Hey shiny!
TLDR: I don’t get people.