Services like SES Inbound are only available in 2x US regions.
AWS isn't great about making all services available in all regions :/
At this point, is there any cloud provider that doesn't have these problems? (GCP is a non-starter because a false-positive YouTube TOS violation get you locked out of GCP[1]).
[1]: https://9to5google.com/2021/02/26/stadia-port-of-terraria-ca...
It is an extremely fundamental level of incompetence at Google. One should "figure out" the viability of placing all of one's eggs in the basket of such an incompetent partner. They screwed the authentication issue up and, this is no slippery slope argument, that means they could be screwing other things up (such as being able to contact a human for support, which is what the Terraria developer also had issues with).
Also, who’s using email-based OTP?