C++ has goto, Java has “break <label>“, nobody uses it but you see a lot of generics abuse.

I’ve seen break label a handful of times for nested loops. Whether that was the best choice is of course always up for debate. It’s definitively possible to replace and not a necessary language feature.

Maybe it’s a good thing it’s not widely known, generics are trivial to discover.

What can be classified as generics abuse in Java?

Using generics anywhere only a single type is ever used. The ambiguity really just hurts readability and creates a landmine for future engineers that think other types can be used willy-nilly and things will behave as they should. Especially if some optimizations get done underneath that assume or asserts some set of types, but doesn't enforce them at the API level.

Using java is abusive towards generics, they didn't deserve that?

I've literally never seen them. Not even once.