Comment by roughly

EVs are cheaper per mile than ICE, with the notable drawbacks that the range is lower, the refill time is longer, and the batteries mean the vehicle weighs more. None of those 3 matter for Amazon deliveries - they’re doing local deliveries (in stop & go traffic, where the efficiency benefits of EVs are even more pronounced), they sit in one place overnight, and for cargo vehicles the weight difference isn’t as much of an issue. Amazon’s got a history of investing in long-term logistics projects (there was an article here a while back about their investment in shipping paying off during COVID), so I’d imagine they’ve penciled this out and are doing it for financial reasons. The company is notoriously focused on financial efficiency, but not necessarily short-term financial efficiency.