It's like none have noticed all processors, even gaming centric ones, come with a bunch of cores these days. Athlon dual core is not exactly a recent innovation, it's archaeology. So all the trivia and "yeah but..."
+ Gaming and a few other tasks mostly do not benefit from more cores and tend to be extremely GHz dependent. Thanks to massive GPU parallelisation we're left mainly CPU bound.
+ Even gaming pitched "Extreme" SKUs are disappointing from a GHz PoV
+ We haven't been in MS-DOS mode or had problems serving 120 OS background processes for a very, very long time indeed.
+ Power and heat have still gone wildly up despite the switch to cores not GHz
So, processor manufacturers hopped off the GHz race for well known reasons. We're now a decade on from that and GHz is about the same like they have stopped thinking about GHz entirely.
It's not unreasonable to have hoped to have hit 5GHz without wildly unrepresentative cheats hidden under the desk, or that they would have kept at least a few percent of their research chasing some more Hz as well as cores.