The camera is definitely annoying but it’s how they try to work around the content protection HDCP stuff. They generally cant just sniff HDMI traffic because some content, like Netflix and Blu-ray, encrypt the stream. It’s possible to intercept and decrypt traffic, but it would have to be reencrpyted before being sent back out and require a special liscense to do and it’s just such a pain.
The simplest solution is to just have TV manufacturers throw some addressable LEDs on the back of the TVs. Super simple, super cheap, the signal is already decrypted and analyzed in the TV anyway…..but instead this exists.