My opinion is that the overall demeanor of desktop user interfaces have steadily become overrun with that of mobile UIs. The "mobile first" mantra has taken a toll on desktop computing, and it's difficult to measure because the desktop computing of a 2019 unmolested by that infantilizing influence (as you rightly put it) cannot be seen from the timeline of reality.
But most of us who have been around for a while can imagine a modern computing environment that still treats desktop computing as desktop computing (and not just large form factor mobile computing).