I agree with this. I'm running CasaOS on a Pi4. Having the initial ease of one click installs gives you a great start, then you'll start to find that you need to manage some port assignments, then you'll start learning about Docker environment variables, then you'll be managing custom installs.

Awesome-Selfhosted is a great resource. Just browse and try something interesting.

My own recent journey went like this:

Run AdGuard
Add DokuWiki, Navidrome, Mealie
Set up Cloudflare Tunnels
Add FreshRSS, Homer, SearchXNG

I also have Nextcloud on a VPS, but the fun is on the Pi.