> Literally, a minute ago I saw a tweet from a guy is very well known, and dedicated his life for one thing. And he's working really hard.

He is tweeting. That means his goal is to portray a certain image. Given your impression, that is part of his intended image and he almost certainly does not work as hard as his social media makes out.

(And, if he is that well-known, he might employ people to take care of his social media)