Why do so many of these always follow the old world ways of this world's history, especial...

Why do so many of these always follow the old world ways of this world's history, especially if it's supposed to be a different world OR is just an entirely made up world!? It's hard to see ones that don't. And I love the ones that I'm able to be lucky enough to run across. It gets on my nerves.
But at the same time all I can do is shrug if people are still stuck there. I mean it IS the year 2021 and everyone still holds the tradition of where the woman always has to take the man's last name after marriage, and that the children should always have the man's last name regardless of marriage. And always assumes it so. Then looks confused when it DON'T happen that way. I wonder in what year it'll be when THAT is completely broken. Especially because of the reasoning behind THAT tradition across most of the societies around the world. Probably not in my lifetime. LOL! ╮(￣▽￣)╭Although I am one of the FEW that did NOT go with that bias tradition.