Or, we've learned that even the biggest web companies can now be built with fairly vanilla technology and that obsessing over clever bespoke scaling schemes is largely a waste of time.

I think it'd be more accurate to say "Even /fairly large/ web companies can now be built [et cetera]". Good luck putting Google on AWS. Or (relevant to the name of this website) AWS.

I think now you could even build a fledgling Google on AWS. Once you start getting real traction then you may outgrow it but there's really no point in even talking about those steps until you have a few million users beating down your door.

... in the sense that the typeface of famous books is worth studying as an example of how to write a good book?

It does raise the question of whether you even need any real ingenuity on the back end for this sort of startup...

Thinking that you need ingenuity is often the root of problems.

you probably need some to create it though