Yeah I don't even like Ninja, and I still hit the free subscribe button because why not?
As someone a couple of years older than you... I had to work a bit to get into Twitch and understand its appeal.
For the most part, what I personally get out of it is learning from players that are better at me in competitive games. As a format for that sort of thing I think it's generally better than a YouTube tips and tricks type thing, and it's something I can have on a screen as background noise while working.
I only do a little esports watching, mostly Rocket League as I don't find FPS to translate all that well as the basic format is jumping from one player POV to another at the whims of the casters who are trying to convey how the round is playing out. As much as I love playing R6 Siege, it's too much effort to watch and make sense of.
I don't spend that much time watching guys like Shroud whose main draw is just the pure aiming talent and reflexes (granted he has amazing game sense when he wants to as well, but most of the time is playing intentionally stupid to meme on people so it's not as engaging as it could be for me).
DrDisRespect I find legitimately funny in small to moderate doses, so I'll click on him from time to time.
As far as 'real' sports viewing, I've been watching less NFL and Premier League/Champion's League stuff the past couple of years, and have spent more time watching instructional/technique stuff on YouTube for sports I play recreationally.
The social sempai streamer notice me stuff I don't really get into. I can kind of see the appeal for a certain sort of person who always liked watching their friends play video games. A decent streamer will be legitimately more interesting to watch playing a game than your average friend.
But yeah, fundamentally I want to play, not watch. But I can play better occasionally watching.