While this may not be a popular opinion, I find Go's type system to mainly benefit the compiler in optimization and be of minimal benefit to the safety or correctness of the program.

Any non-trivial Go project will have interface{} sprinkled all over [1], which effectively gives you the guarantees of a dynamic language with the syntactic overhead of a typed language. Truly the worst of both worlds. While I realize it's a tired argument, Go desperately needs generics in some form or another. It would remove most criticism from the language while substantially improving the correctness of programs.

[1] Here's an example with an LRU cache. Just search for interface{} : https://github.com/hashicorp/golang-lru/blob/master/simplelr...