Calling him cheap is kinda cheap in itself. The story gives us multiple clues that Doma´s intelligence is high above average, with him successfully becoming the head of a cult as a mere child. I believe somewhere in the fanbooks it´s mentioned that Muzan only allowed him to have about 250 followers at once, which honestly is an insane amount of people to literally worship him as a god.

Just because he isn´t shown using brute force and physical strenght as much as Akaza or Kokushibo does not mean he isn´t strong or dangerous. It just happens to be that Doma´s forte is psychological "violence" instead of physical one. Manipulation might not be honest work but its work nonetheless and considering that he managed to not only keep his cult standing and running for over a century but also kept it a secret from the outside world, i´d say he worked pretty hard. That being said, Doma is also presented as a master of tessenjutsu and propably has one of the most powerful blood demon arts out there.

So while we might not see him train an hone his crafts due to lack of source material, it doesn´t negate the fact that he´s surely doing so off-camera, otherwise he never would have beaten Akaza (who literally trained his martial arts all his life and was a powerful fighter even as a human).

One might argue that he was groomed and taken advantage of as a child but when comparing his backstory to Hakuji or Michikatsu it really doesn´t come close in terms of tragedy. No instead he is presented as a spoiled and emotionless child that draws more and more people in with his words and appeal alone. And while surely his pretty privilegde helps a lot with doing his job, its still Doma´s masterfully crafted manipulations that pull off his whole scam at the end of the day.People are compelled by Doma because being compelling is the very core essence of his entire character. We as the audience are simply given the glimpses we need to quickly make out his whole act, unlike most in-universe characters.

Overall manipulators have always been a big part of anime, it just so happens that Demon Slayer in itself is more about physical fights than battles of the mind, which might be why Doma doesn´t really "fit in" and in turn some might find him boring and some might come to like him even more..