Back in the medieval ages when a woman was married to a man, they were basically considered property for my understanding and treated like an extension of the man’s person and family. So it was customary for women to take the man’s last name since they were being joined to his family. But now here in the 21st century women are fully independent and last names don’t really seem to mean much of anything. I mean what is Smith or McGregor or any last name really mean anymore? Especially in the digital age, lots of people have digital usernames like SarahSmith1727373. So the last name clearly doesn’t mean much anymore… Which leads me to wonder, why do the majority of women still take the man’s last name? Especially when some of them have a horrible last name? I have seen some butt ass ugly last names recently, like Fink, Weimer, Slotsky/Slotsky, Hiscock (no joke this is a last name), Hardman… And then you hear the woman’s name and it’s like something way more reasonable and less stupid sounding like Kingman, or Harrison, Walls, etc.
My wife did, despite me saying I’d rather she not. Me changing to her name was not legally possible in our situation (me US citizen, her JP citizen, both living in and married in Japan). (Edit: What I wanted to do was change to her name, but that doesn’t happen unless I give up US and my other citizenship, apply for and get JP citizenship, and choose her maiden name as my name or do that but a name combining hers and the sound from the start of mine rendered in kanji).
Her reasoning was that we could quickly and easily remove basically all doubt that we are related with just what ID we both always carry. Her usecase was one of us being critically injured or something and being able to gain access in the hospital or something else like that.