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.
As someone who's worked with react for years, I'm convinced that react itself is the problem and there's no way to educate new people on the proper way to use it without essentially teaching them everything the abstraction is intended to do for them. Why should newbs have to care about mutations and state dependencies when the api is apparently designed to help them forget about those things?