This is my take as well.

They're sticky because they stay focused on their specific domain, and they work well.

I also really don't understand the value pitch on "6 apps no one can use" in the post.

I publicly host Seerr and Jellyfin for my family, and they use that combo just fine. They explicitly don't get access to see any of the sausage making under the hood.

Given this doesn't support music yet (according to op) and you still need to host plex or jellyfin... what is the value statement here over seerr?