I think I disagree here. Technology is very much a key part to solving most of humanity's problems. It always has been. Technology is what drives humanity forward. You can look at every empire in history and you will find that at their peak they had some kind of technical advantage over others. Conversely, their fall tends to be correlated with losing that edge.
Silicon Valley thrives on startups spending money on all sorts of crazy stuff that accidentally succeeds once in a while, courtesy of plenty of investor cash to keep that going long enough to find out. The successes are wildly lucrative. There are probably more than a few future billion $ unicorns being nurtured to success in the valley.
However, as soon as unicorns succeed they turn corporate. I think Google is a great example of this. IMHO there's a clear difference between what Google accomplished technically before and after their IPO. At this point it seems they are mostly milking tech that they built/acquired around or before 2005 (search/maps/youtube/android/ads/etc.). It's not that they are getting nothing done but they are accomplishing far less at far greater cost since they probably spend more than ever on R&D while having increasingly less to show for it. They take less risk with their projects and their comfort zone has shrunk to the point that they felt a need to park their more wacky initiatives under the alphabet umbrella, outside of Google. Of course, this may end up being a clever move if some of those efforts succeed. But I would look outside of Alphabet for likely unicorns.
This CEO was employed to look after the cash cow while the Google founders focus on the more exciting stuff in Alphabet. He's not there to build the next Google, merely to keep the existing one going. Stagnation is not unique to Google. Many companies suffer from technical stagnation. Very few companies actually survive more than a few decades. In the tech world, things are trending down not up in terms of longevity.