Yeah, I have a few of those. There's this one girl in particular who I've only recently realised is actually really horrible to me. She tends to say a lot of unnecessary things like "oh, you're looking a little tubby" or "is your hair thinning?" The thing is, I never know whether she's joking about it or not, and she's only like that with me. She also outed me to someone at a certain point in my life when I wasn't really ready which was really... not cool. But for some reason I still feel compelled to be friends with her. I guess it's probably because we've been through a lot together/travelled together/she helped me through my darker days back when I was closeted, etc.. In addition to that, we move in nearly identical circles and so it's hard to not be friends. It's not like I can say "I can't be friends with you anymore" because, well, it's more trouble to not be friends with her than it is to be friends.
Another one is this one friend who's a little bit tiring. By "tiring" I mean I almost always regret catching up with the guy because he's so whimsical and tends to be really in-your-face and I constantly have to entertain him if he's at my house. Like OP's friends, he has a tendency to give an excuse at the last moment to not come, especially to things that he seems to be really keen for. It's not like I don't I love the guy, but when he still farts in my face (I'm not even joking) and eats all of the food in my fridge (can't be bothered asking) it's exhausting.
So yeah, I have some friendships that I feel I have to make an effort towards. But at the same time, I'm sure that at some point they had to deal with me being annoying to them in some way, and they've have stuck with me through thick and thin. It doesn't mean that I have to keep in regular contact with them, so if I only have to deal with their crazy antics once in a while, I think I can handle that much.