I understand what you’re saying, and it probably is a factor, but just one of many.
And it’s not just men, women take this into consideration as well.
I met DH when I was young and didn’t really take it into consideration, and as it turns out, he doesn’t have any of that. I don’t really either so it has made for a somewhat lonely upbringing for our kids, no big family parties etc.
My situation is that my family was quite small anyway, but then a lot of them died. Friends are all quite scattered, no one big friendship group.
Husbands situation is that his family is quite fractured, no siblings and no relationship with cousins. One absent parent, other parent now deceased. As regards friends, I met him when he had just moved to my city for work, so didn’t really have any friends here. I think he thought I was really popular and he could slot into my established friendship group, because at the time he met me, there was a kind of group vibe, but it was just a moment in time, it wasn’t an established group, so obviously that never materialised for him.
Overall it’s been fine. It’s just one factor out of many. I don’t think it will be an issue when dating.