Look up the apps, Kodi(media centre) and Kore(a Kodi remote).
Kore running on a phone or tablet can cast video, over to a Kodi instance running on a HTPC, IIRC(If I Recall Correctly * May have remembered this part wrong).
Newpipe(PipePipe + Tubular apps) can also show an option to cast to Kodi too.
GrapheneOS is banned by Google from casting to Chromecast devices, AFAIK(As Far As I Know).