I've found reliably "turning on" with pmset to be hit or miss. I can't remember the gotcha I ran into if it was that you had to have your laptop lid open or something else...
Yes. If macOS is asleep or idle, pmset won't get triggered. It is best used with caffeinate.
I used it for a museum installation where every night I'd turn it off before they cut the electricity and turn it on in the morning just after electricity is switched back on: it was a way for me to be in peace with my conscience (though after some tests, the mac didn't bother getting switched off by cutting out the electricity).