I don't think it's becoming a black box at all. Classes were more intuitive, sure. But, they really allowed you to write some gnarly and inefficient code. I've always felt that React lets people get away with not fully understanding JS fundamentals. It's very apparent when dealing with some bootcamp devs who never had to write production vanilla JS. One example is that you can get away with not fully understanding that with classes you're dealing with different instances of objects.

Understanding hooks did take effort. Only after I read Dan Abramov's article a few times was I able to write hooks w/ deterministic results. It is a MUST read. Don't let these Medium authors you've never heard of confuse you with their understanding and basic examples. https://overreacted.io/a-complete-guide-to-useeffect/

To me, understanding Hooks feels exactly the same as learning Physics in high school. You not only have to keep track of variable scope in your effect callbacks. You also have to keep track of function iteration. All the variables in your dependency array are like variables in a physics function and as they change so too do the variables you reference in the function scope.