IDK, don't you end up with a bunch of extra costs? Like you're going to literally pay more money because now you have cross region replication charges, and then you're going to pay a latency cost, and then you may end up needing to overprovision your compute, etc.
All to go from, idk, 99.9% uptime to 99.95% (throwing out these numbers)? The thing is when AWS goes down so much of the internet goes down that companies don't really get called out individually.