Would it be possible to compile a small desktop program with an internal web engine to run SketchUp free on? I think Spotify along with some other softwares works this way. This could combine the benefits of web technology (easy to work on, easy to update etc) with some of the benefits of desktop software (runs in its own window, no shortcut conflicts, feels like a proper program etc).
If the web app was cached for offline use and file reading and writing were local this could solve a great deal of the problems with the current SketchUp Free.
Yes, I worked on progressive web apps for a few years I think they will become more common and it would be interesting to see what the Sketchup guys come up with in the future.
I think @jbacus has already alluded to something new in the pipeline at some point but cannot mention what it is right now. I would not be surprised to see some sort of halfway house between online (free) and desktop (paid). I think a subscription desktop version would be nice, similar to Creative Cloud and Autodesk.