Plus, these chips with two CCXs also has double the PCIe lanes 40! So a number of NVMe drives, GPUs, 10GbE etc... can run together without fighting over lanes (and that's without double bandwidth of PCIe 4.0).
It does still feel weired calling 16 core/ 32 thread CPU with 72MB of cache 'consumer'.
As DDR5 is coming out next year, that will mean a new socket, limiting the upgrade path for the CPU, RAM & Motherboard. Although, 16 cores ~4.5ghz shouldn't be a problem for the near future (maybe 5 years even). Same goes with the PCIe bandwidth.
Edit: Just done some checking, I appears the 3950X has 24 PCIe lanes (16+4+4), but they are twice as fast, so not far behind the current 2nd generation ThreadRipper!
The chipset multiplexes up to x16 lanes of "stuff" onto the x4 chipset lanes from the CPU.
All of this is physically determined by the pinout of the socket and none of this can change unless AMD moves to a new socket. What did change is the speed of the lanes - x4 lanes on 4.0 is twice as fast as x4 lanes on 3.0.
AMD, like Intel, likes to pretend that chipset lanes "count" as full CPU lanes, arriving at a total of 36 effective lanes. But that's nothing new either.