I'm sure the cost of getting all of the devs to write Python that safely runs without GC is far les than 10% of your AWS bill for Python services... Maybe at Instagram it is, but it won't be at 99% of companies.

It isn't like most Python devs you interview are going to have any kind of a reasonable answer for "How would you write XYZ - with the GC disabled?" I'd bet the ones with a good answer cost >10% more on average.