Is falling in love in the romantic sense a mistake? Is it just a plain stupid thing to do? 50% of marriages end in divorce now so maybe it is stupid.
Falling in love is not a mistake. Expecting it to never change is a mistake. Both halves of the couple will change with age and experience and that cannot help but change the relationship. Sometimes, adaptation may not happen or be possible and then breakups happen. My wife and I are not the same people or in the same relationship that we were 25 years ago (we've been a couple for just over 26 years and married for 22 of them).
To answer the broader thrust of this thread, I was raised in a "traditional" home for the most part. This became painfully obvious when Mom died and Dad was left on his own. He simply was not equipped to do it and went through a failed second relationship before meeting the woman he was married to up until his death (my sort-of stepmother, though given that I was almost 40 when they married, she never really filled that bill for me). He definitely seems to have fit the pattern you're getting at.
Not sure if my generation will be better or worse in this regard. I am quite capable of living on my own and taking care of myself because we lived apart for so much of the early part of our relationship (at one point, with her Down East and me in Ontario) and I've been there, done that. In fact, I've often said that if, God forbid, this marriage ends prematurely (divorce, death, other circumstances), I'm probably out of the marriage game. I'd want a "girlfriend" as company for trips, concerts, etc. (yes, and that, too

) but not a fulltime, live-in spouse unless we were "perfect for each other" and I know that such a thing just does not exist. For me, a wife is a partner, companion, co-parent, but not a substitute mother. But am I typical? No idea.
I'm glad to see you talking out your pain over this
@Kimmio and hope having this place to do that is a help. Take care and good vibes.