Still sailing H16 a lot in Europe / the Netherlands
However new cat sailors seems to fancy sophisticated cats (Foiling ...) more than good old H16's nowadays...
Have a lot (>10 ?) H16's on our club - majority seldom used. Probably same problem in USA: only approx 20% of our members are regular sailors.
However - as my H16 is 1992 built - I'm often asked what cat I would buy when I needed another/new one: I still found no answer. It's all about fun & sailing. I don't want to spent much time adjusting repairing (daggerboards) just need a reliable cat. [broke a bow tang recently - the first damage in many years !]