Personally i am someone who didn't play a wide variety of horror games although i enjoy fnaf, poppy playtime and resident evil series and i'd like to try hello neighbor next time.

But i notice that unlike most genres, horror games tend to be generally less appreciated or played by people and remain mostly niches except maybe to resident evil to some point ?

I'd like to have your opinion about it

Horror's hard to do properly without relying on an overabundance of tropey "scares" that don't stick with you and opt to instead make you jump. There's certainly a place for both, don't want to say otherwise, though mascot horror is definitely WAY easier to churn out and since they don't stick with me at all I don't care for them. Plus everyone copies one another ad nauseum until you have to sift through nonsense to find the gems. But tenser, eerier experiences like the Silent Hills and the Clock Towers of the world are more my speed, because they can be terrifying AND engaging.

Even still, I'll play most any horror game that comes out and I'll just rank it accordingly.

Mascot horror already existed with silent hill with the rabbit one and later slender man.

I'd argue that there's a difference between "mascot horror" and "horror game mascot", but to each their own