You are right that in modern society it’s much harder to make and maintain friends. Really you have to think of it in terms of “closeness” or intimacy. Have you talked about only good things with these people? Or have you opened up about maybe some deeper or darker topics? Have you been to each other’s house? Have you helped each other do something important and difficult? Being a friend is almost like an imposition. You need to be able to rely on and support each other.

being a romantic partner seems to be the only way to be a priority in anyone’s life.

I would say this may not be the ‘right’ way to consider the question. But it’s hard to explain, even more so in English. The aim should not be to be a priority. It should be to be valuable to one another.

I know a few people but I’ve one friend. One, that’s it. We’ve been friend since we were kids (now nearing our 60s). We don’t live in the same country anymore and, naturally since we also both try to reduce our impact on the environment by traveling (a lot) less, we don’t see that often. Also, we both have our life(s), friends, and family. And that’s fine: we seldom meet, we even seldom chat like we used (spending countless night discussing philosophy and politics (we both are complete opposites on that matter) and spending countless hours writing to one another the moment we could not meet IRL anymore) but we are friends. We both know from experience the moment we need it the other will be at our door, virtually our in person depending the situation. To me that’s friendship: we don’t spend a lot more time with many other persons, but that doesn’t change a thing. I mean, we can and have put such or such discussion on hold, sometimes for a year or more and get back to it the moment the opportunity arise like if we had left it the night before…

It is something we learned back in the 80s and 90s, before we had readily available ‘Internet’ and before everybody and their mother switched to email and later on to social networks, back when we had to use snail mail to discuss despite distance and wait for our letter to reach them, and wait even more to receive their response. Not just the two of us, many other people used to do that back then. Being patient and being fine with only getting a few minutes here and there and make the most out of those.

like, I don’t (expect to) spend all my time with my spouse… 34 years and counting together. A liberty we both consider a key part in respecting one another’s. She has friends and activities I can’t be bothered with, like I have mine she can’t be bothered with. And we both are fine with that. We’re a couple but we remain two individuals that will do stuff on their own, including spending time with other people and having fun without their partner.

All of that to say we should be fine not being the constant ‘priority’ of someone we truly care, and appreciate whatever time we can spend together, no matter how little.