For my homelab: portable state. I don't use this image specifically but I use many others.
I put docker-compose files in ~/configdata/_docker/
The docker-compose files always mount volumes inside the ~/configdata/ directory. So let's say irssi has a config directory to mount I'd mount it to ~/configdata/irssi/config/
Then I can just run a daily backup on ~/configdata/ using duplicati or whatever differential backup tool of your choice and be able to restore application state, easily move it to another server, etc.
Sure, this makes sense for a server, but irssi is a client. This is just a program running on your computer. You don't need a "homelab" or any nonsense like that.
I put docker-compose files in ~/configdata/_docker/
The docker-compose files always mount volumes inside the ~/configdata/ directory. So let's say irssi has a config directory to mount I'd mount it to ~/configdata/irssi/config/
Then I can just run a daily backup on ~/configdata/ using duplicati or whatever differential backup tool of your choice and be able to restore application state, easily move it to another server, etc.