There are several reasons for this. I think the biggest reason is that broadcasting is a very difficult thing. Maybe not technologically but the person who broadcasts live needs to be prepared very well.
Usually, amateur live broadcasts aren't that good and don't turn into great content for the audience.
But Twitch is one of the companies that has achieved great success by broadcasting live.
Opened in 2011, Twitch is the main communication channel of many professional players today.
Thanks to the type-giving mechanism, professional video games can generate huge revenue. Players who play well get their money back easily.
Professional players say that Twitch's audience is more milked and stronger than Youtube.
As with Youtube, an important point in Twitch is the number of subscribers. The more subscribers you have, the higher your viewing rate for your next video or live stream.
Twitch Sub Badge is therefore important. I've shared the information above. Good luck.