The "at most a few years from profitability" after a period of what, 15 boom years?, doesn't sound that great as the 3rd place contender.
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]
[1] https://www.statista.com/statistics/983299/worldwide-market-...
[2] https://www.statista.com/statistics/1328893/global-file-shar...