Sometimes, I wonder if the whole "we got lucky," thing was just that they did get lucky, but only for long enough to bootstrap them into having spent enough time around each other to get attached. My experience of human nature is that everyone is actually really, really close to the same once you get to know them.
I don't think that follows, because people adjust to the improved situation[1][2]. To take a case where the gains are pretty undeniable, nobody celebrates regularly that they are much less likely to get polio or some other disease that used to be much more common. We just adjust to the new reality, and keep complaining about the diseases we do get today.
>But only long enough to bootstrap into having spent enough time around each other to get attached
Yea, in my experience that's how a huge swath of relationships usually work, especially for people who haven't been in many relationships or who have big enough relationship gaps that they feel the need to cling. People getting caught in relationships that aren't all that great but "hey, wtf else are we gonna do, at least we aren't tearing each other's throats out, right? Maybe having a baby will help us love each other." We've all seen it, many of us have lived it.
I'm arguing that the proliferation of dating apps is helping that go away. Either because a highly specialized interests based site like OkCupid lets you zero in on quite nearly the perfect partner, or because you can shotgun across a zero cost app like tinder, you're far more likely to find an actual meaningful relationship.
For the record, I know there's a higher tier of relationship than "familiarity breeds love" due to personal experience.
My partner and I met via Tinder after both of us had cycled through a lot of dates, and we catch ourselves saying "god damn are we lucky" over and over and over again. They say you make your own luck by increasing your surface area, yea?