Biking infrastructure is only useful in big cities where your distance to work could be quite short (within 5 miles or so). The average American commute distance is 41 miles. It just doesn't make sense to build out bike infrastructure very many places in the US.
Trains and changing the roads to make it easier for cars to drive themselves make a lot more sense.
I don't think Google cares if the Fediverse succeeds or not. All they care about is that it can be indexed and people will be able to show Google ads on their instances.
Google doesn't have a Reddit equivalent or even any other social network competitor (anymore; they killed them all). They explicitly chose to exit that entire concept of products.
The only reason XMPP mattered to Google at the time was they were trying to compete with Apple for messaging on mobile devices. XMPP meant that Android devices using Google Hangouts/Chat/Gmail could chat with users on other platforms/services while Apple's chat app could only do SMS.
I guess what I'm saying is that Google is mostly irrelevant from the perspective of the Fediverse other than the fact that it can index and maybe give priority to discussions of certain products/topics like it does with Reddit currently.