Google makes fuck all revenue from Drive, it never mattered. EVERYTHING at Google, most notably the cash fire that is Cloud, is funded by Search. This is the first time that is in danger and over 25 years they never came up with a fallback plan. This is an unmitigated disaster and purely the result of mismanagement.
Also the comparison is between Google versus Dropbox (the underdog David that's analogous to OpenAI), not Google versus Amazon or even Google versus Microsoft.
Google is 51% of office productivity software market versus Microsoft. Microsoft is at 47%, Dropbox isn't even listed. [1]
Dropbox has a decent share of the personal cloud storage market but has really failed to expand beyond that vertical or become significantly profitable. [2]
The point is Cloud is still 100% subsidized by Search, and if Search loses even 5% of market share in the next 12 mo it is a disaster as GCP cannot fill the gap as they are still losing money. The velocity at which they are losing money is immaterial to the fact they are not nearly ready to plug a hole if Bing take share.