If the solution you're building is business-critical then you already have a problem day one: you need high-availability. That means you need at least two servers. As soon as you add that additional server your troubles have begun. Doesn't really much matter whether you add 1 server to your setup or 100.

Your problems compound if you have to consider disaster recovery (DR) and need an offsite location you can failover to. Now you have to contend with data replication and all its concerns.

So even if your application only has a few dozen users things can get quite complex quite fast. AWS makes it simple, practically push-button. Deploying in multiple Availability Zones (AZ) is a no-brainer, and it isn't horribly difficult to deploy in multiple regions, complete with data replication. All while having no servers to configure and maintain. No containers to contend with, no Kubernetes to fight with. To me it's the most stupid-simple solution available today and it's ridiculously cheap! At least so long as you test before you deploy for world exposure!