It's been an unpopular opinion but I've contended for a long time that if Go had map/filter/reduce from the onset like it has copy and append, most people screaming for generics would have been silenced.
But doesn't that require some level of generics? This is an honest question not rhetorical / a retort.
Go has several generic functions like append() or make() baked into the compiler (https://golang.org/pkg/builtin/). When people are asking for generics, they're asking for a language-level mechanism for defining additional generic functions beyond these provided by the compiler.
I'm talking more along the line for Map/Filter/Reduce support and why those weren't included in Go originally.
Yes. The distinction is that there are two ways to implement map/filter/reduce: either as additional built-in functions or in std. Only the second way requires language-level generics support.