[pestaa]

There are advantages when using RDS other than scaling.

The performance dashboard is especially nice.

The reusable sets of configuration is convenient and the UI makes it easy to compare original vs. changed values.

The instance upgrade is not seamless, though, it is normally scheduled for the next maintenance window, unless you decide to apply and reboot immediately.

I agree the service is expensive, but setting up a db server for production takes a lot of time and expertise.