Yup, it's super ironic of AWS to be complaining about Microsoft charging extra for their technology when it's used off their own platform. When AWS themselves are constantly evolving their tech stack to make themselves as sticky as possible. Heck, at least MS is licensing their technology to be used off platform!
But AWS is practically a cult at this point, you're expected to worship at the cardboard alter and if you're not getting the efficiency you expected from moving to AWS you just need to make sure you're maximising your use of AWS products. If you don't make all your workloads AWS native, then you're a bad acolyte.