If you have a lot of users sharing a small number of servers in the cloud, Kubernetes and Docker can help.

If you have one process hitting one Raspberry Pi, they won't help you.

Part of what you need is a plain English, low jargon, directory that briefly explains each piece of technology, and which problem that piece solves. It would need to be opinionated on when to use and when not to use different pieces of technology.

I don't think any directory like that currently exists. If someone built it, I would go to it a lot, and endure lots of ads in order to learn about pieces I don't use yet. If only someone would build this.