I fly out of a small-to-medium-sized airport in Canada and I've never seen it happen there. The idea of one person being responsible for both tower and ground in the busiest airspace in the US is absolute insanity.
Agreed, but isn't O'Hare the busiest airport in the US?
Edit:- It's Atlanta.
YVR has had flow control every day for years now, and closes the class C to VFR traffic on virtually any sunny day now, due to staffing problems. It's been happening since long before COVID, but that made it much worse. The controllers simply refuse to take on more traffic than they can safely handle.
Lots of pilots here have been complaining for years about how the US controllers are so much better, they can handle much more traffic, etc.