> Somehow Google greenlit this as a standalone product amongst many other options...
Even before the “internal incubator” that this came out of, Google hasn't been known for doing a single exclusive offering in a space, so this probably wasn't centrally green lot (because otherwise “internal incubator” makes little sense), and it's release wouldn't (even if it was) exclude another Google offering in the same space. The competitive process you imagine just doesn't seem likely to even approximate the truth.