Basic single-core scalar-only workloads of my own corroborate the grandparent, as well as most of the other benchmarks I've seen. My own 5600X is "only" about 50-60% better than my old Haswell i5-4950 (from Q2 '14) on this note.

But the scalar speed isn't everything, because you're often not bounded solely by retirement in isolation (the system, in aggregate, is an open one not a closed one.) Fatter caches and extraordinarily improved storage devices with lots of parallelism (even on a single core you can fire off a ton of asynchronous I/O at the device) make a huge difference here even for single-core workloads, because you can actually keep the core fed well enough to do work. So the cumulative improvement is even better in practice.