There is code that doesn't `constantly cast ti and from Object`, most code won't need to, anyway. Generic information is kept during type-checking and then is discarded, this can be considered an optimization. There are some warts that appear because of erasure, but I believe you're wrong in implying that most developers care (most java developers, maybe scala peole have more issues because of erasure).

That it doesn't have reified generics like C# does not make it a dynamic language. Go doesn't have generics at all, but it's still a static language.