I second the recommendation of using Jellyfin.
Additionally you can use something like the Unified Remote app to make your phone control your computer instead of a mouse. Want to turn up the volume just use the volume rocker on your phone. You can also turn your phone screen into a large trackpad. Very convenient for watching media. I think there is an open source version called KDE Connect but I haven’t used it yet myself.
Well then use VLC and a remote control program like Unified Remote or KDE Connect and use your phone as a remote control for volume and mouse.