Problems of conventional IPTV/OTT boxes with AOSP
If you know a bit about Android IPTV/OTT boxes, you should know that they originally had a smartphone operating system installed. And using mobile phone apps on those boxes causes huge problems for users. Try to go to Netflix and find something there without connecting the mouse to the set-top box. Almost all mobile apps have problems when used on Android set-top boxes. That's why Android TV was developed, and all Android TV apps have been adapted to use the remote control. In fact, selling set-top boxes without Android TV is a sign of a lack of concern for the consumer and a sign of a cheap Chinese product.
But official Android TV imposes its own limitations. Both in terms of the capabilities of the software, which must be certified by Google, and in terms of the price of the end product.