But again, I still severely doubt you've never run into a problem with Go's lack of generics. I ran into it after about 3 months of working with Go. Maybe you didn't find the work-arounds problematic, but that doesn't mean that the original limitation (no generics) doesn't cause problems. You just choose to accept the work-arounds as the "right way" of doing things.
If you haven't already, I would recommend looking at Rust or another modern language that has generics to see what sort of benefits you can get out of it that you can't directly get with Go. Personally the fact that if T implements an interface I won't let you use T as I is pretty silly IMO. Rust lets you do that with the From trait, and you can even do it even more generically with the From trait using a generic T.