Hosting as in having some code deployed to some machines is indeed cheap. Keeping a large app like g.docs up and running, especially without breaking the bank, is a bit more tricky.
Of course, that applies to literally every piece of production software ever, but keeping a webpapp running really isn't that hard, it's honestly the bare minimum of competent software development, if you have a team of SREs up at 3am triaging the site every night you're doing something wrong. Now of course, when you get to google scale, you will encounter unique problems, but if you're at google scale your business has more than enough revenue to pay for the costs.
Also, how would you be generating revenue from these users? Just do what google does and run ads on the side? Then what's the difference?
Spinning up containers is like the bare minimum I'd expect from an ops engineer, I wouldn't call it "trivial" but it's the job.
> Also, how would you be generating revenue from these users?
That's a business question, not an engineering one, if the businesses doesn't have a plan for revenue then hosting costs are irrelevant.