It never stopped.

Just takes backwards steps from time to time with major architectural innovations that deliver better performance at significantly lower clock speeds. Intel's last backwards step was from Pentium 4 to Core all the way back in ~2005. AMD's last backwards step was from Bulldozer (and friends) to Zen in 2017.

7GHz is ridiculous and probably just a false rumour, but IMO; Intel and AMD are probably due for another backwards step, they are exceeding the peek speeds from the P4/Bulldozer eras. And Apple has proved that you can get better performance at lower clock speeds.