Everyone codes however they want. What works for you might be different for someone else. And wanting to do it while interacting with an audience or streaming themselves creating something they already know how to do are all completely fine things.
Woz said of his time building blue boxes purely motivated by intellectual curiosity:
> I was so pure. Now I realize others were not as pure, they were just trying to make money. But then I thought we were all pure.
Tech is so impure today it reeks. Bring back the hackers who build things for fun. Bring back the nerds who don't care to make money.
I’ve seen streamers do exactly this (while interacting with their audience through chat).
Why did you interpret “stream themselves coding” as “typing code flawlessly on stream”?
Nope. Anybody who streams themselves coding is not a real coder. Coding is not rapid fire typing memorized boilerplate code to techno background music. Real life is not Mr Robot. When they do it at the same time each week that's the reddest of red flags that they're performing an act. It's all staged. As staged as professional wrestling is kayfabe.
Real coding doesn't happen on a strict schedule. There's research, design, and testing to be done and mistakes to be made and corrected. Typing out the code is the least important part of coding and by far the least interesting. But real work doesn't hold the attention of techbro posers long enough to sell ads now does it.