I hear this is a common refrain and, in my case, it's proven 100% correct.
Granted I'm almost 40, but my 20s were all parties and friendships and 30s have been, basically, just family and kids, which is fine, i would like to have at least one good friend to have a whisky with once a month though.
I find the issue is a time one, friendships take time and, with 2 kids, I just don't have much of it.
Bit worse in my case as I also live in a different country AND for the past 5 years have lived in a rural village. living in the city before didn't help much, I also work from home, maybe with a job it would be a bit different.
My other lifelong best friends from life and childhood live in different countries and while I would visit them when single and had more money, it's not possible now.
How about you stackers, if you've managed to forge new friendships post-30, how did you manage?