Rejecting templates does not mean rejecting generics.
This is provably incorrect.
The position held for many years by the language authors was[0]:
Generics may well be added at some point. We don't feel an
urgency for them, although we understand some programmers
do.
Generics are convenient but they come at a cost in
complexity in the type system and run-time. We haven't yet
found a design that gives value proportionate to the
complexity, although we continue to think about it.
Meanwhile, Go's built-in maps and slices, plus the ability
to use the empty interface to construct containers (with
explicit unboxing) mean in many cases it is possible to
write code that does what generics would enable, if less
smoothly.
The Go 1.18 release added type parameters to the language.
This permits a form of polymorphic or generic programming.
By run-time they mean compile-time? There shouldn't be a run-time penalty right?
Also, is there some measure of the additional compilation cost now that generics has been added?
However, the original announcement makes the intent of the project clear: "Not yet", not "never". They were always planned to be accepted into Go. But not before an acceptable solution was found.
They have successfully been able to add major features such as generics without breaking 1.0 compatibility, and the trend is to continue than way. Well there is no major language feature in sight in fact.
Also major figures of the Go team (Russ, Ian, Rob, Ken) are gone.