Its main purpose is to prevent malware from booting. In my experience its main purpose seems to be preventing me from booting things I want like ventoy flash drives, nvidia drivers, and Linux distros that don’t support it. Same goes for tpm module. Its main purpose seemed to be the switch keeping win 10 from upgrading. I turned them both off and haven’t felt the strong need to turn them back on yet.
That said, and my bad computing habits aside, you probably should turn them ON. I’m not sure they will do all that much realistically speaking, but if it isn’t getting in your way (and it shouldn’t), then ON isn’t a bad default state to be in.
I’m out of the loop. Why not virtualbox?