Amazon Web Service plays the strategy "catch me if you can" (e.g. new services launched last week). Google is trying to catch up, if they want to beat AWS they would need quite a few differentiators (e.g. like buying Firebase).
The problem with this statement is that Amazon is largely matching firebase functionality. They just announced streaming JSON out of dynamodb, and the new lambda functionality means you can trigger events on changes and push out updates. It wasn't explicitly stated but I viewed this as a firebase competitor.
