Open Source Tool to Deploy Rails on EC2

Please check out HiveGrid project. It is designed to simplify deploying Rails 7 apps to EC2.

It’s nice to have a tool to simplify EC2 deployments, but would it not make more sense to use Kamal instead of Capistrano?

You need Docker to use Kamal. For HiveGrid, there is no need for Docker, Load balancer, Traefick etc.