My understanding is that Google “rates” its leaders by the number and types of projects they develop. Ergo there are a lot of people working on disparate items that often overlap, because it’s “their” project. Once the project completes, they get their credit, stop caring, and move on to the next. It is said this is why google creates then kills so much. It’s by design, essentially. The products they keep are the ones that make the most ad revenue.