why do people spend time watching someone play a video game and occasionally talk into the air

I enjoy watching people play Dark Souls, Outer Wilds, etc for the first time because it's the closest I can get to playing a game for the first time again.

What the hell is a hololive

What if, instead of being themselves, the streamer played a character? Now, what if we went further, and made that character an anime girl? It turns out that there are quite a few weebs who will donate thousands of dollars to those anime girls! And so hololive was born.