I can see how it could be a responsibility. It's a good responsibility though, that enriches your life - as opposed to an annoying responsibility that's forced on us.
Unfortunately, I've been in a mental place where I haven't really been up to it for a while though. I think part of being a friend is continuing to have things to talk about, and to do that, you need to continue to take in new things, learn things, do things, and I've been too burnt out on life to do any of that for a while.
A lot of the time, when I don't talk to people, it's not out of annoyance or no longer caring about a person. I still think of them, wonder what they're up to, and care for their well-being. It's because I don't have anything to say cause I've gone through a period of just feeling blank or unhappy, and I don't have much to say, and I don't want to come across as boring or too negative/complaining too much. I've been feeling blank mostly out of anxiety for my future in terms of career, being able to be good at anything, ever being interesting enough or whatever you need enough to be attractive. I'm not in the right headspace to hold a conversation. So I just say nothing until the feeling passes...but unfortunately, life also passes while I'm waiting, though.