I didn't get married until my late 20s. High school was rough, college better, and then things kept improving, similar to your arc.
One thing that is weird to me, and this could obviously be anecdotal/recency bias, but it seems like a lot of younger guys have problems making friends with girls. Just normal friends - co-workers, classmates, etc. For all of the joking in this thread about seeing women (or men) as hook-up objects, some younger people seem to have a problem with chit-chatting the opposite gender in a completely platonic way.
I had this conversation/lecture/TED Talk with a early-20s cousin a few years ago at a family reunion. He had not brought his girlfriend to the reunion because she had suddenly become his ex-girlfriend and he was kind of complaining about it. I basically said, "don't you have a number of female friends you could call up and get somebody to go out/run around with you for this kind of stuff?" and he looked at me like I was speaking in tongues. Like it didn't occur to him to have a number of platonic female friends.
To go back to your point about it being easier to hook up with other people now than at any point in history, back in the 90s, I found making friends with a lot of women a great way to well, meet more women. My places of work were usually sausage fests and/or the women were married, so I'd make friends with the married women, make friends with female neighbors at apartment complexes, etc., and just by acting like a normal, decent person, you will stumble across a female friend who loves to play matchmaker. At the very least, you'd get invited to parties, dinners, etc. where you'd meet more women.
Here in 2025, it's even better - just be a decent person, make a bunch of female friends, be Facebook friends with them, don't post batshit conspiracy theories or misogynistic bullshit on your FB profile and feed, post nice comments/responses, etc. and you are exposed to a whole shitload of women of all ages and needs/wants.
Youth really is wasted on the young.
If I somehow ever end up divorced, I will be using the hell out of these tools to easily find my next ex-wife.