Tell that to the folks running Threadripper or Epyc CPUs.
9-)
The huge hashrates you see out of some Xeon based machines are usually multi-CPU and need to be divided by the number of CPUs - then factor in that any Xeon that manages more hashrate than the AMD Ryzen 1800x is a MUCH MORE EXPEN$IVE CPU that on a cost-basis comparison should be getting compared to the Threadripper line or the Epyc.
On the other hand, some older used E5 Xeon based machines can be had pretty cheap for the hashrate - just watch the power consumption....
Yes, some old xeon machines are will worth for cpu mining.
Someone has a rack of Winterfell servers up for sale - I almost pulled the trigger on it, but when I checked the power requirements I found it needs 3 x 30amp 220 circuits - which I don't have available in my current place.
Oh well.