It's a site that shows a bunch of text, a few images, and then loads and plays video. What features does it need on a TV that it's so hard to implement?

Edit: I know which ones, and they have very little to do with Cobalt, but with the fact that even high end TVs are often worse than a Raspberry Pi, and can stick around for a decade. But this is nothing ditching Cobalt would fix.

E.g. you can't run 4k video on some models that can technically show it because there's not enough CPU and RAM to run the browser, the video, the decoder, and the DRM at the same time, the video stutters