First of all, I want to say that I DON'T think TES should be a copy-paste of a sightly different Earth with magic.

What I mean is that many things in Nirn work like Earth but the explanation is totally different. For example, both planets (Nirn and Earth) have a cycle of day and night (24 hours), the year lasts more or less the same and have seasons (some people in TES complain about a particular season and it wouldn't make sense to have a city named Winterhold if they didn't have a winter).

Plants grow better when basked in sunlight, people also need it, etc.

Earth displays this phenomena because it orbits at a certain speed around the Sun and rotates over her edge at a certain tilt yet in Nirn the same has/needs very alien explanations.

The Sun instead of being a hole (which makes it harder to understand day/night, seasons...) should be a high concentration of magicka that makes it have significant mass and thus makes Nirn revolve around it, the other stars could still be holes to Aetherius and Magnus could have escaped through one of them so magicka could still leak, and everything could happen the same way, yet almost everything that works as Earth does wouldn't need obscure explanations.

I think of it as a middle-ground between our physics and TES'. For me, the "problem" boils down to adapting a concept that exists in Earth (in reality or in fiction) to a world that works vastly different yet the results are largely the same (why vampires on both worlds get harmed by the Sun even though they are so different?,etc)

What do you think?

Regards.

The sky as we perceive it is an oversimplification of reality created by mortal mental stress at the presence of multiple infinite planes.

I already knew that explanation but then:

Why is there night and day in the same fashion as Earth's?

The OP is exactly that, shouldn't it be more convenient to have an Earth-like system instead of having a radically different explanation?

Night and day are caused by Nirn rotating. Nirn can not rotate around Magnus, because that would change Magnus to the center of the Arubis [censored] up the Tower.

Don't know why we should reach for a heliocentric theory when a geocentric model works just as well here. Nirn does in fact house the Heart of the world and is the source of a lot of cosmic woes.

I even think it should, but the purpose of ES's lore seems to be unconvenient and radically different, or "weird". Remember, this is a place where the simpler explanations sound boring, and thus "wrong"!

Edit: at this point, ES adopting your logic may break the fantasies of many. Broken fantasies are not pretty.

Unless you're getting into the meta territory, I don't see how or why people find the basic premise of the cosmology that difficult to grasp. Even at is most base explanation, it isn't something too terrifyingly complicated along with some other bits of lore.