> If I were doing rock climbing, I still wouldn't enjoy talking about rock climbing the entire day with my rock climbing friends

Um, have you actually tried? I have a "rock climbing" friends group, and it's rare that we talk rock climbing outside an actual climbing outing. Some of them are at the climbing gym 2-3x a week, some of them 1x a week, some join only once every 1-2 months. But what we do a lot is hang out just for dinner, for some hike on the weekend, going to a concert, whatnot. Climbing was really just the initial excuse to meet, by now it's only a detail we all more or less do now and then.

Maybe you are overthinking this.