Nothing new.
In 1999, for some reason I had become the "go-to" computer guy for many of the Veterinarians on The Peninsula[0]. They were all running late 1980s, early 1990s IBM PCs (486 "ValuePoint" machines, for the most part), with SCO Xenix, now updated/graded to ver. 5.x[1] ... The Vet Practice Management software was provided by IDEXX, but was built by PSI ... Needless to say, IBM, SCO, PSI and IDEXX all claimed the other three were responsible for any Y2K issues that may (or may not) crop up.
Most of the Vets, assured by these four companies wonderful bedside manner, switched to Cornerstone or Avimark software running on Win98. I cheerfully set 'em up and then dropped out of that world (except for a few cases). Xenix had worked great, was never an issue in all the years I took care of them. Windows ... well, you know. I wasn't in the mood for the inevitable headaches.
[0] The Peninsula is the local name for the bit of San Andreas Fault fractured rock roughly between the Golden Gate and Palo Alto.
[1] Note to the youngsters: That's the proper, original SCO, not the later, perverted SCO of litigation fame.