That problem is not unique to Google. The bigger the company, the bigger this problem is. Big corporations are primarily concerned with keeping share holders happy. Share holders by and large are not very technical. Nor are most executives. And there are several layers of management in between them and the people actually coming up with new stuff. Communicating anything technical and the sense of urgency about doing something with that information to those people is very hard.
For any meaningful budget to be allocated to some new and exciting but unproven thing, a lot of very busy people in that org tree need to be in agreement that that's a good thing before anything happens. That happening is just not very likely. It's literally easier to get investment outside corporate hierarchies. That's why startups are a thing. Google files lots of patents that they will probably never do anything with. And that's just the ideas they've had that get patented. Most of what Googlers come up with never gets actioned in any way.
In this case what happened is that a bunch of smart Googlers invented something, wrote a paper about that, and then some external people read that paper and got inspired. Multiple startups got busy working on those ideas and Google ended up sleeping through the whole AI revolution until belatedly realizing they needed to get their shit together. Probably around the same time their shareholders noticed that something was up. Now they are in catch up mode. And they'll probably pull a thing or two together. But the point is they are reacting to the outside world and not acting on their own insights or inventions. They are one of many big companies that now know AI is a thing.
They'll likely miss the next big thing as well for the same reasons. Even if they invent it.
It's not about these people being irreplaceable or not.
The key word here is all of the paper's co-authors have left (8 in total). That's a sign of talent bleeding. and likely isn't limited to that team alone.
It's an indicator that Googlers are finding better and more attractive opportunities outside the nest.
Depending on the scale, that can be fatal.