[throwaway7679]

> There has been a significant decrease in desktops in the last decade.

Indeed, but not because phones have gotten any closer to desktop work.

What good is a phone, today, when using multiple monitors for 3d modelling, video editing, programming, spreadsheets, flight sims, or some such? None whatsoever.

And there's no apparent trend toward it, so it doesn't make much sense to predict when it will be reached.

Desktop usage will likely continue to decline as phones, tablets, VR, and whatever other devices continue to supplant them _in certain areas_, but that's insufficient to render them obsolete.