You can run a media service for example jellyfin on the same PC as the client.

Installers are a thing on windows, on Ubuntu you can install software with apt. It wasn't packaged for my distro so I downloaded an archive unzipped and dropped it in /opt

Not sure why anyone would absolutely need to understand Kuberetes or even docker.

Plugging a PC up to a display has been a better TV for a while now.