I've seen a lot on people in twitter discussing wether people should do "kinks"(?) in pride because they might scar the children for life and other arguments. Also calling people like the youtuber Big Joel pedos for thinking this is not a huge deal.
What happened? Maybe this is an american thing but since when have kids been brought to pride?
Those are pretty subjective measures though. What's "too small" to one person isn't going to be to another... like some people will think thong bottoms are way too far and some people think it's no big deal. I even think the "see through" thing is kind of a grey area. A lot of bathing suits get a little see through when they get wet. Hell, lots of people don't like wearing bras and don't feel like they need to cover themselves up if, god forbid, an outline of a nipple is visible.
Breasts and nipples are completely different than genitals, there are double standards around people with flat chests vs breasts (mostly men vs women so it's very misogynistic based) but genitals aren't acceptable for either.