Oh, I meant it more in terms of "can you count on them as optional services". Because they aren't optional, and yes, it takes non trivial amount to replicate t

Oh, I meant it more in terms of "can you count on them as optional services". Because they aren't optional, and yes, it takes non trivial amount to replicate them... but funnily enough, several of them have to be replicated elsewhere too. NAT gateways usually aren't an issue, KMS for many places can be done relatively quickly with Hashicorp Vault. IAM is a weird case, because unless you're building a cloud for others to use it's not necessarily that important, meanwhile your own authorization framework is necessary even on AWS because you can't just piggy back on IAM (I wish I could).