Looking into Amazon's power bill might be a useful start: Fugaku is listed as drawing 28 MW in OP. It's more power efficient than most, but to an order of magnitude that's a number we can work with. Amazon's power usage for US-East was estimated at 1.06 GW in 2017 [1] (at which time they also apparently owned about a gigawatt of renewable generating capacity [2], now closer to 2 GW [3]).
Either way you slice it, Amazon likely owns at least an order of magnitude more FLOPS than any single system on the top500. What they presumably don't have is the low latency interconnects, etc., needed for traditional supercomputing.