The #1 rule is clearly not show energy, show enthusiasm. It's the #1 rule for a subset of content, like MrBeast. The content world is a big place, and the silent majority has no interest in loud and obnoxious.
Right. Take Asianometry-- a channel dedicated to economics, politics, and tech in Asia. Very high quality stuff. He goes into deep detail about a lot of technical stuff.. and as you can imagine his delivery isn't anything like a showman. He can be monotonous but if anything that is likely preferred by his audience, given his niche.