I also searched some key words and seen not much people answering questions around those topics.
What is the main reason? Any advice?
I enjoy participating in HN to discuss technical topics and whatnot, but I don't count on it as an information source for embedded work.
You'll find a few people here noodling with various toy projects and the Rust Evangelism Strike Force pops in from time to time, but that's about it.
Is there a reason? I don't have one. Probably because everyone else here is trying to create the next Uber and isn't down in the trenches poking at flywires.
Maybe try /r/embedded if you want to chat about things or ask for homework help because your professor is too busy. The S/N ratio is pretty decent there.
I am interested.