Wrt creating new people, as indicated by the PIDs beginning with P… (this years): one reason this happens in my experience is because the new PID is suggested by the system if it does not find a suitable person. Especially true when adding a marriage partner. This may not be because the vital information is too sparse.

By the time I've decided to add someone like this, I've already established to my own satisfaction that it's both a real person and they did marry. Dealing with persons in England and Wales it's usually someone found as a named partner mostly as "wife") in a UK census (1841-1921), and confirmed by a civil registered marriage (a free source is FreeBMD or one of the paid platforms). It'll be backed up if at all possible by newspaper notices (for the date, but on a good day also the parents and places). With luck, I'll already have the relevant birth and pre-marriage history from census or other data. I'm actually pretty reluctant to start adding people into the tree on my own cognizance if at all possible.

But I notice that the system isn't so good at finding people without baptism or church wedding data. That's mostly when the self-made PIDs come into play.