Earlier quoted context omitted.
Indeed. My old self-imposed rule was that upgrading was a waste of money unless I could get at least twice the performance. Manufacturers have generated high benchmarks by throwing "moar cores" at it but even the best chips have barely a 40% single-thread increase over my seven year old Haswell build.
40% single thread increase, but most likely 100+% increase in core count. CPU manufacturers did not slap more cores on a CPU to get high benchmark scores, it's just one of the few viable options for increasing CPU performance.
That means those extra cores won't really help day to day performance.