"We have committed to spend $2 billion with Google Cloud over the next five years and have built our software and computer systems to use computing, storage capabilities, bandwidth, and other services provided by Google, some of which do not have an alternative in the market." There's some numbers for you that Google wouldn't have provided (as far as I have seen).
Is it not possible to build your own "alternative in the market" for $2 billion?
edit: I should point out that this doesn't account for ramp-up. It would obviously take awhile before things would be to a point where it would be even comparable.