I think your take hits the nail on the head. Most people have zero interest in running their own website.we live in a world where people have no clue how things work. They just want it to work and not have to understand how.

People could change their own brakes and oil too. But how many folks want to? Not many. It doesn’t provide value to them. Just like a personal website wouldn’t provide value to them. Hence, like you said, social media pages are their “personal website”.