I don't get why people want to stream to shitty devices. Why not just buy a gaming console or PC that can actually play the damn game without depending on an internet connection.
Really you are asking why don't you spend $200-500 console or $750+ on PC, instead of using a device that you already own. The cost of entry for streaming is only $50(controller). Besides, Xbox model streaming is seen as an alternative way of playing when away from your console or PC. The new Luna service announces by Amazon really pushing streaming as an alternate way into gaming for a really cheap barrier of entry. If you can't see the appeal for some people, you are probably in the camp that thinks buying a next-gen console is stupid when RTX 3080 & 3090 will blow away the power of said consoles. It's all about cost, especially if you're not that passionate about gaming.