Scala is an interesting language, I liked it and used it for years.
But it is for me a good example of an academic language rather intended to test new paradigms and features, its reading is clearly not accessible to those who don’t spend their days on it.
Some features of the language are clearly anti-productive for reading, implicits for example.
Concerning Go, it’s a never ending debate, I’m rather in the camp of those who, like you, think that generics are really missing (the other camp argues with accuracy that it didn’t prevent the language to be used on very big projects until now).
For me the main impact justifying the addition of generics is the absence today of a powerful collection system (with maps, filters, etc.).