I was annoyed that my media is only available on my main machine, if I wanted to watch something on my phone or show a photo to someone, I needed to boot it up. So a home server to host files for me and my household seemed logical. Since then I went on a degoogling trip and as part of that, I installed Nextcloud, also very useful. I also do my backups to the homeserver (and then back up the homeserver too).