I guess how it works for me and my friends is we just don’t expect to rely on responses to our messages. We don’t message each other very often. That feels OK to us. It wouldn’t to everyone.
Some of it is probably generational and to do with life stages as well as temperament (we are middle aged women with complex caring responsibilities and/or high pressured careers, and we grew up pre-internet and pre-mobile phones, and are hardly ever on social media - so we have Gen X expectations around text & online interaction, and are also not of the boomer generation who are very diligent about Christmas cards etc)
Someone who is very dear to me hardly ever replies to messages - sometimes we’re not in touch for a year. But then she or I will suggest a phone call and we’ll chat for ages. We meet up about every 2 years and it’s like we saw one another yesterday. This is someone I have known for 30 years, and at one time we had a very close and intense friendship, but we’ve lived in different countries for nearly 2 decades. We couldn’t have kept up the level of contact we had before, while developing new friendships and relationships and careers and families. But the bond remains, because we trust we mean something to one another even when we are not in contact. This deep bond would not have developed if either of us had ended the friendship on the grounds of un-replied-to messages.
I have newer friends who aren’t in text / phone contact much, or who don’t reply to messages for days or weeks if at all, but we run into one another and the bond is sustained by casual, in-person contact.
I also have friends / acquaintances who I like and appreciate, but I don’t feel very close to. Sometimes there is an imbalance here where they consider the friendship closer than I do and are in touch more than I want to reciprocate.
This is a tough one, because these people haven’t done anything ‘wrong’, and I do like them and enjoy them and have a nice time when we see each other, and it’s not that they shouldn’t be messaging me this much. But they are feeling a closeness to me that I don’t feel back with them for whatever reason, and it is clear that they are angling for a higher-touch friendship than I have capacity for.
I have been on the other side of this, too, and it can be painful - particularly when I’ve been in a new place and thirsty for new friends - but it is just one of those things, and I’ve learned to be thick skinned and keep trying to find people I vibe with more, or who have more room in their social circle for developing new friendships.
I’ve spent 30 years in a country where I had no family and had to make my own networks, and I know how hard it can be. I have absolute compassion for people who are finding it hard to make friends, and how awful it is when others’ circles are already full and it’s hard to get in with anyone. What’s benefitted me is to recognise that there is room to have different sorts of friendships - some casual, some close; some intense and some intermittent. And that the nature of those friendships will be in constant flux as life changes for everyone.