Thats not what im doing at all. I even gave a link to AWS documentation of achieving 5-nines by utilizing multiple AZs, etc. I also reiterated this in the comment you responded to above..

What sacrifices you talking about when synchronously replicating to a backup environment? Write latency? How do you deal with that usually? How much is too much? There are strategies to deal with reducing replication related latency depending on level of consistency required.