> I would happily accept that problem if skipping the extra work enhances my chance of becoming a big enterprise in the first place.

And that's the right choice in some cases. But the added up-front effort can be a lot less than the added reengineering effort, and growing into a big enterprise doesn't mean you are immune to disruption by more agile startups.

And, of course, those who are already in big enterprises have different concerns (while premature adoption of the mitigations at issue can be engineering resume padding in startups, deferring it with the hope that it won't be a crisis until it's someone else's problem in exchange for short-term metrics can just as easily be management resume padding in enterprises.)

But how much less work is it do it up front, and continue to maintain and test a multi-provider platform?

I don't think it's 100x or even 20x less work.