I can kind of agree, I know of one couple who are early 30's, got together in their 20's. It all makes a difference as far as I'm concerned especially from what I have experienced being older.
Woman had one DC, bf has two from previous. Issues there at some point because he had to go to court to get access.
Not sure apart from some babysitting, how the gf saw her bf with work etc and her responsibilities, his not the same as not with his kids all the time.
She reckons she left it a year before introducing her DC, i don't think so.
And another part of the story was him at hers and them having sex in the same one bedroom flat she lived in, that her daughter had to sleep in too.
Bf lived with family, gf had to wait for permanent housing.
And has since got a two bed flat, so bf made a clever mood I think, by asking if he could have his DC over there when it is his time to have them, and that's what they do.
And he started staying more often, but also alternating between there and the other place, I call that never growing up.
They since went on to have their own child, which ties him in a bit more if you see what I mean. And he is there pretty much all the time, but to me he doesn't do a lot, yes he works but that is not everything. And he's got somewhere to live without having to lift a finger 🤷🏻♀️
Not the only example I could give, but I have a habit of waffling on.
All I'm saying is, I have seen men do it but only if it's in their own interest!