IBM's semi guys have been doing all kinds of wacky things with low volume chips (and also high-volume, see eg. prev gen consoles).

For example their System/360 compatible mainframe CPUs are doing 5.5 GHz now. https://en.wikipedia.org/wiki/IBM_zEC12_(microprocessor)

Chip design is somewhat like software, adding more people or resources doesn't necessarily make your product superior. Look how long tiny AMD has been putting up a fight.