Some might argue that if you don’t feel sore at all you haven’t pushed yourself enough, and if you feel so sore it takes days and days to recover then you pushed yourself too hard. Finding the sweet spot is important. And I think this applies to strength as well as running and other exercise.
In my experience it's an indicator if I'm doing something enough or not. If I regularly perform an exercise it won't cause soreness. Squat 3x a week, one of those sessions being heavy? No soreness. Squat once a week? Definitely getting DOMS afterwards. Same with running. If get sore after a run I probably took time off before it.
I’ve been doing StrongLifts consistently since Jan 1 and so 3x per week I am doing squats. I still feel soreness despite 3x per week because the weights are semi-consistently increasing. So I think to modify what you are saying, I think frequency is one vector, but another is volume. Or maybe I am still just a beginner and eventually I’ll be able to lift increasingly heavy weights week over week without any soreness!
It's worth noting that some soreness may not be immediate, but delayed. People call this Delayed Onset Muscle Soreness (DOMS), and can come on ~24-48h after a given exercise.
It's not sudden, but can feel that way sometimes when you wake up!
