My ex took my last name, because he had siblings with children and my family name would have died with me. It was a gift to my father that his* grandson would carry the family name forwards. And no, that wasn’t a red flag – we were married for 30 years.
I'll admit when I was in my early 20s, it was a point of contention with one girl I was dating. I was young and stupid, my mom took my dad's name, etc.
But by 30, wiser, less prone to drama, I was solidly in the "who cares, do what makes you happy" crowd.
My wife kept her last name. It's easier, and less confusing for her clients and networking.
Grow the fuck up. Stop being so needy and insecure. It's a bad look.