Nowadays I often wonder if more than 5% of people go multi-user

Who even names someone Administrator? Poor kid.

No worries.
Soon, millions will be sharing a mainframe subscription cloud system, with just shell terminals priced at around half a year's salary and requiring an "upgrade" every 2-3 years.

My PC automatically logs in and the entire family uses that one account. I don't need no security on top of that. You're already in my house

Not since DOS v 6(?). Once Windows 3.11 came out my father had had to upgrade his machine enough times that we had 1 computer for each family member. We literally had hand-me-down computers instead of clothing.

I actually work with people who still have a "family computer".

One guys doesn't even have a computer at home, they have phones and iPads.

No, because the rest of my family had no interest in using it.