But...They kinda share this...religion... Polytheism... Aedra and Deadra... Half the people love the deadra more than the aedra. No speak of heaven or hell.
The Daedra and Aedra have no differences other than how they were involved in the creation of Nirn. Any other differences are created by them. There are Good Daedra, that attempt to respect their followers for whatever reason, and the Nine Divines don't do much to help Tamriel anyway, other than when someone is going to destroy it.
But I'm quite sure the knowledge for this stuff can be found in other places you know?
Yes, it can. There are Greek, Roman, Breton, French, English, Gaelic, Mongol, Pacific Islander, Assyrian, Norwegian, Swedish, Saami, Hindu, Christian, and many different pagan religions that have been used in the TES world somewhere. There are also African tribes, Amazonians, and Native American ideas in the cultures of many TES races.
Don't make these generalisations, as it makes it hard to get this, if you're basing your opinions on that sort of thing. And it really annoys me
way back then when there weren't even telescopes??
The TES world is not set in the medieval era. People will tell you it is, but as we don't know where it's set, we are unable to compare the technology level to a time, and as a result we cannot say when it was. Yes, the medieval era had swords. But it did not have airships.