he is a very minor character in christianity
In the text, definitely. In the practiced religion (especially in America), not so much. And even in the text he has a much larger role than in its predecessor Judaism.
I think the pop culture versions of religions have become so deeply ingrained that they became a part of many adherent’s actual beliefs. For example, ask the average Catholic to describe hell and see how long it takes for something from Paradise Lost to pop up.
even in the popular depiction he is not nearly on the same level, as he was created by God, is not omnipotent, omniscient, unlike God, etc.
Why would that disqualify him as god-like? Polytheistic religions had gods of varying strengths, many created by other gods - the Greek pantheon is a tangle of lesser gods created by greater ones, and even Zeus came from Chronos, a Titan (which is somehow different from a god).
The whole assigning of godhood seems completely arbitrary to me. Archangels are more powerful than many full-on gods from other mythologies yet somehow don’t count, whereas even humans could have been (or will become) gods in other lives in religions such as Jainism or Mormonism.
My point is that what constitutes a god differs between religions, and the Christian claim of monotheism uses a very narrow definition of god that excludes the many supernatural beings described in their religious texts.
If you use the standards of other religions, one could easily argue it’s a polytheistic religion - the Trinity, or one divinity appearing in multiple forms, is similar to other religions generally considered polytheistic.
It’s an endless debate because both sides talk past each other due to disagreeing on the basic definition of the term.
That’s a matter of debate I’m not at all qualified to get into. They have some very out there beliefs that they understandably don’t advertise to outsiders, and that only became common knowledge with the advent of the internet.