Mine is that the useState hook is an actual plague on the entire React ecosystem. Regardless of your opinions of React, if you wanna use something then use it right.
Nominal typing was a premature optimization. Product types should be structural and row polymorphic. And if they had been, dynamically typed languages nevdr would've needed to exist and wouldn't have waited so long to smuggle types back onto their data structures. That said, i'm kinda glad shell scripting languages exist.