It sounds like you've had a very different PhD experience than I did. Perhaps a difference in fields? My PhD in physics was probably the most humbling experience I've had in my professional life. I went from thinking I knew everything to learning that I knew nothing. To me that's one of the most important parts of a research education, to become aware of what you don't know and be provided tools to try figuring it out.

The most disconcerting part for me was coming back to society, realizing that no one actually knows what's going on most of the time, even when they think they do. I wish more people had the same humbling experience I did (not saying, by the way, that we need more PhD students, just the similar experience).

It's curious why you'd think that the only reason for doing a PhD is to contribute faster. Contribute faster to what? The author says he's having a lot of fun with his PhD because he gets to work on topics that are not immediately tied in with Googles business model.

This is exactly why we need PhD students doing fundamental research, because no one can see the immediate benefit. Because on the surface it has no value at all - so who else would look at it if not curious PhD students with little to no financial incentives.

Constraining possible research breakthroughs to what someone thinks is valuable a-priori, seems very naive and counter productive to me.