I came back to the top to write a leading question: is Instagram going to be the main social network used to communicate? That changes the purpose of following. If not, then here’s my take regarding content alone:

Do I care about their lives? I’ll follow back. Do I like their content? I’ll follow back. Do I not care about their lives and don’t like their content? I don’t follow back.

My interests have major overlap with some opposing ideologies and if they make it a part of their content, I’m not following them. If they post low effort bullshit about their outdoor alcohol without doing any proper photography technique, I don’t need to see that snapshot of their day unless they’re a core person I care about.

If you don’t follow back, they’re probably going to forget within a day. “Oh I don’t check it often”. You’re also allowed to unfollow people if you don’t like their content later. It’s not a big deal. If it’s a big deal to them now, they’ll either figure out it isn’t a big deal later or they’re always going to prioritize something I refuse to. Follow count should be natural but it will always feel like a competition and a measurement of success. Always has been, on every social platform.