Like you said, when you're out meeting people you naturally gravitate to the age range you're comfortable with. Like, I wouldn't go to a club or bar where I know most of the people would be around my kids' ages. Nor would I go to a place where I know most of the people would be around my parents' ages. I think the age filter on a dating app allows us to to decide which "club" we want to go to.
And really, for me, age is not the most important thing. I have my age range set, but if someone 1-2 years outside of either end of it showed up in my potential matches and there seemed to be some real potential there, I wouldn't be like, "Oh, he's too young/old, too bad. Swipe left and move on." But at the same time, I don't want to match with a 22-year-old when one of my kids is about to be 22 himself. Aside from it just feeling awkward and uncomfortable to me to think of dating someone young enough to be my son, I'd be worried that as a result, we'd end up with more of a parent/child dynamic than a truly equal partnership. Throw sex into that mix and it just feels bad to me. That said, though, I am a parent. If I didn't have kids, I may not look at matching with a 22-year-old the same way. It's interesting to contemplate.