That's a bigger question, like why do people watch streamers in the first place. It's not for me personally but it's a huge worldwide multibillion industry so plenty of people enjoy it and / or aspire to be it.

I enjoy a handful of streamers for a few reasons:

* I get to experience games I wouldn't normally have time for: I work full time, and as much as I love games and always make time for them, I still have a finite amount of time to make and a solid chunk of that time has to be devoted to multiplayer games, since it's a big part of how I meet my social needs. And even then, some games that are quite fun to watch for me are games I don't necessarily want to play? Like I love watching people play things like Lethal Company, but I don't have a friend-group to play with, so a streamer is great for that. Also horror games usually have really interesting worlds, but uh... I am a chicken shit LOL

* It also broadens the number of games I'm exposed to quite a bit. Many a time I have tuned into a stream, watched it for awhile, and been like "okay this actually looks really good/fun/interesting" and turned off the stream to go buy it on Steam. I've just bought Claire Obscur because I initially thought it was Yet Another Damn JRPG (objective 1: go to class, final objective: kill god) but I was thoroughly incorrect, and corrected by watching some streamers and an essay on it, and I'm really excited to play it now.

* Additionally, a wild third option: sometimes it's nice when working remotely to have a stream on for background noise. It hits your brain in a way that's vaguely similar to hanging out with a friend when you're both doing completely different things and just... existing together. It's completely fake of course, the streamer has no idea who I am, but it doesn't need to make sense to feel nice to my brain.