They are really good at keeping demos as demos

I don’t know, a lot of Google demos and papers introduce techniques that are productized fairly soon, just usually not by Google.

The implementation that manifests itself as an extremely creepy, downright concerning level of dubious moral transgressions isn't nearly as publicly glamorous as their tech demos.

It’s just a hiring article.

Hiring to produce more demos, to hire more to produce even more demos...

As long as they choose not to work elsewhere, it seems effective for Google.

Yes. As long as the hirees do some actual work in between producing demos, this even makes sense as a hiring approach.