Yeah, but you don't get to pick just AE if you're doing a fair comparison, as Bitcoin serves pretty close to every cryptocurrency user on the planet. It's reasonable to compare it to the sum power usage of every financial institution willing to handle US dollars somewhere in their infrastructure.

You don't get to pick just the bitcoin exchanges as well. If bitcoin ever became a standard, you would by your logic have to include every financial institution that pops up to service bitcoin, custody bitcoin, swipe bitcoin at a store - and include all their headquarters etc etc. That whole layer you include for fiat will also exist for bitcoin, only, now we have the much larger energy expenditure to maintain bitcoin vs fiat.

No it's not reasonable. Bitcoin is moving a tiny fraction of the value of what just Visa by itself is processing (nearing $10 trillion in total annual volume; 141 billion transactions; 65,000 transaction messages per second). They also store a record of every transaction they process, along with vast troves of connected information.

American Express is a full-stack institution with its own processing network, own bank, own card issuance, own customer service, etc. It also serves a ton more people than Bitcoin does. If the comparison is unfair, it's in Bitcoin's favor as Amex does significantly more.