I would be surprised if they haven't. i9-9900KS is still based on renamed Skylake core from 2016 scarred by Spectre mitigations at 14nm optimized to death.

My guess is that they were too optimistic with 10nm and no one started an alternative project on 14nm when the time was right.

They already claim +18% IPC on Ice Lake (because they basically dropped at least one generation and fixed security issues at least partially). When they resolve problems with the process (either by succeeding with 7nm or switching to TSMC) they will be very likely competetive again.