Skylake (6th) came out in 2015. It's just that due to the 10nm delay we then had Kaby Lake, Coffee Lake and Comet Lake all being refreshes of Skylake on the same process until we got to Rocket Lake (11th) - a backport of a 10nm uarch to 14nm with the somewhat predictable power issues. Only with Alder Lake (12th) we actually got the first real new uarch on the process it was designed for since Skylake.
I've been hearing that since Skylake, at every single processor generation that the gains are too modest. That's more than a decade at this point.