is it weird for other old-timers to see this happen? The number of PMs has exploded, and their scope has gotten much smaller. It seems like every form in an app has its own PM now and every one of them is fresh out of school.

PMs used to be different. They were excellent performers from engineering/marketing/business that caught a bigger view of what was being built and had a gut feel of what needed to be built. It seems like those folks don't have a place to go any more and we continue to beat the cross-functionalness out of folks while saying we aren't.