In the long run I don't see anything but open screen protocol actually being competitive. There's dozens of different cast things, but imo it was access to the web & web platform that made Chromecast so capable & powerful, and nothing else is remotely as competent. https://github.com/w3c/openscreenprotocol

There are however little more than tech demos for it. There's still a significant body of unresolved questions. Theres very limited amount of effort going in. But there are some very nice libraries too, such as https://github.com/youtube/openscreen-rs .

Not an answer for most people for today, but if folks are feeling agentic, this is where I would burn my tokens. Your timing is actually quite incredible; I picked up my project again & have been burning the last tokens of my weekly quota on open screen protocol today!

(Don't get me started on what a frelling turd show MatterCast is. Last I checked it was for native apps, and had no means to distribute or find programs, only could work with apps already on the castee. Miserable evil capture-computing shizzle, with zero aspirations to ever allow the just works interoperability that made Cast so amazing. Truly captured device ecosystem, of Official Partners anti-consumer villainy. Vomitously disgusting, makes me feel much worse about Matter in general seeing how wretched that looks.)

What I don't understand is what the actual hardware needed to run on a "regular" TV is. Do I need to buy a Raspberry Pi 4, connect via HDMI and cross my fingers that my TV remote will work with whatever open source TV software is out there? I am surprised that I can't find something more like a complete product for sale with software + dongle + remote.