An analogy that might appeal to machine learning enthusiasts:
The quality of friendships and romantic relationships can be thought of as the dot product of two high-dimensional vectors. The elements of the vectors describe mutual interests, attributes that are important for relationships, etc... The dot product means that as your interests and personalities are more aligned, the relationship can become stronger.
(Aside: There is good scientific evidence that the opposites attract myth is just a myth. The converse is true. More similar people find each other more attractive.)
But here's the rub: by default the vectors are already fairly aligned by the simple fact that we're all human. We all have some baked-in interests, wants, and personality traits that align well with the same in the fellow members of our species.
Secondly, most people meet people that are physically near them, which means that statistically, their "vectors" will align significantly better than chance. Like... way, way better.
I can sympathise with the author of the blog article. I get it. I really do.
I'm a political refugee, and three decades later, I still don't quite fit in with the people in my new home. Combine that with esoteric interests and a shy personality, and I start to look like the author an awful lot.
But I've had surprisingly little trouble living with romantic partners from hugely different backgrounds. Literal polar opposites of the planet, different religions, you name it.
Turns out that they're just... human. They want hugs and romantic meals, trips overseas and back rubs. Same as everyone else. It really doesn't take much at all to "align". It's basically our wired-in default!
Essentially, the best we can do is optimise this dot product, but there isn't anyone on the planet that will reach 100%. Despite this, we can get a surprisingly good match without even trying, because we're all already set up for being a 90% match for each other. People like the author are complaining about being an 80% match, not a 5% match.
I got to my 90% by simply finding partners that were also political refuges and/or expats. That's all it took. I didn't have to change my personality or become a different person.
To put things in perspective: There are people that put up with abusive spouses. Seriously, think about that! If you don't think you can get along with a friend or a romantic partner, just consider for a minute that other people find physical abuse tolerable, because it's just one dimension in a high dimensional vector where everything else mostly aligns. I mean... sheesh... just... don't hit people? You're already way ahead of a surprising fraction of people just by doing that one thing.