Agreed. Nothing actually typical at all for regular "just offices".

I do remember working ~25 years ago at a place that did have those two kinds of outlets. Our computers and monitors would be on the UPS+generator ones, while desk lamps, office lamps etc. were not. But it was specifically because the offices were on-site w/ the two data center complexes the company had and the building I was in happened to also be wired into that whole setup. Not every other one was either, only that one and the 24/7 NOC.

I only knew this was a thing because my office mate's computer was in the wrong kind of socket. One day his lamp stayed on while the computer turned off and for me the other way around. Soon after we heard the diesels starting and had to close the window coz of the fumes.

At full capacity of the data center, the absolutely huge UPSs could run the data center for all of 10 minutes. So that's how long the diesels had to actually start and take over.