The problem is, most of these sorts of services work via a network effect. Especially chat: You use the one all your friends are using. Payment is the one that all your accounts and stores you go to support.

Running a bunch of your own competitors is self-defeating when it ensures you don't have the network effect. Google Talk worked mostly because it was in Gmail, and everyone had Gmail. People who never used it had it, because Gmail.

Maybe that works for their internal politics, but not for the users. I've given up even trying new Google offerings

Never said it was a good strategy ;)

Darwinian Product Strategy?

Quick, someone should register it and publish a book and make a career giving talks about it...

Feel the same. One example is Angular Typescript and then there is AngularDart, both are used by teams in Google.