Earlier quoted context omitted.
Yup this is it. Google's bleeding money on these initiatives to preserve its crown jewel: search. More and more people are using Amazon and other services first to find stuff they need - which means lower engagement with search and lower effectiveness of paid ads. If Google can build some of these services themselves it could potentially maintain its reputation as the first stop on the customer journey.
As a slight anecdotal counterpoint to your comment about Amazon, while I often buy the product eventually from Amazon, I initially search "amazon $productname" on Google because I don't like Amazon's search.
Sometimes I think that just putting things like all alibaba products (maybe also put others who also allow this) on your own better functioning site at a 5% or so markup would be a huge opportunity.