There is no reason to not run AWS offerings like RDS and Elasticache on ARM for instant cost savings. Performance is comparable to Intel/AMD so I see no reason

There is no reason to not run AWS offerings like RDS and Elasticache on ARM for instant cost savings. Performance is comparable to Intel/AMD so I see no reason not to use ARM even if your own code is not compatible. I have no doubt that AWS will also switch over services like DynamoDB, ELB and countless others which don't let you chose machine type to improve their cost basis.