Setup Nextcloud via Docker... with everything baked in?

You can have a look at my guide here: https://help.nextcloud.com/t/howto-ubuntu-docker-nextcloud-talk-collabora/76430

This is running everything in Docker except for a reverse proxy and certbot.

Docker-compose with a group of containers is as “baked in” as you’ll get with Docker as each container is really only supposed to run a single process. With Docker-compose, you can run them collectively as a group.