I have tried both Smart TV and Android Streaming Box hardware to run various setups - both of which are theoretically capable - but in practice fall short compared to the Steam Deck experience (which I already had lying around almost gathering dust)
The oudated 2019 NVIDIA Shield TV Pro is still regarded as the best in class - despite not supporting many modern things like AV1, HDR10+, HDMI 2.1 or Dolby Vision.
I ended up using a Homatics Box R 4k Plus for everything video-related which _does_ support all of the above quite well, but it unfortunately has so many software issues which prevented me from using Steam Remote Play or Moonlight which is why I ended up settling on just using a docked Steam Deck for that use-case.
I switch between the two, which is pretty annoying!