Firebase is revolutionary. If you haven't used it, it means you can remove your reliance on all the server side logic you currently maintain. It is a huge philosophical change but is the perfect complement to serverless architectures.

This is smart by Google. AWS AppSync provides much of the same functionality but gives you the benefit (if you already know Graphql) of Graphql. Or, it forces you to learn about graphql, which is also the downside. Forcing Fabric customers into the firebase ecosystem makes it look like this was a cheap acquisition from Twitter after all.

The huge win with either platform commitment is you simply focus on your data and forget about the challenging problem of syncing that data across all the platforms. That's (multi client sync) a big, big, big challenge and no one does it well on their own.