As a former teacher of younger kids, that feature probably makes them 10x less likely to be forgotten/lost. (The size is "youth 10-") Agree it's kinda gross, but kids are wired differently.
Growing up we were on a swim team and my brother would chew on his goggle straps while waiting for a race. My parents bought us some flavored goggle straps lol. I think they were blueberry flavor...
Goggles aren't even something designed to go in your mouth like a mouth guard, but I guess they knew kids chewed on them so why not
When I played flag football in elementary school we were required to wear a mouth guard but we didn't have these fancy things. So what we did was put pre-sweetened Kool-Aid mix in them and now it's no wonder so many of us developed bad teeth.