Without any external powers, which clan wins.
The Uchiha have the Sharingan.
The Otsutsuki have the Byakugan although we aren't sure if it even does anything without chakra fruit influence.
Here is the thing that I find stupid about this argument (no offense to you specifically OP. I've seen several people make this argument):
The Uchiha are just a subset of the genetic line of one particular member of the original Otsutsuki (Kaguya). They basically are Otsutsukis themselves. You can argue that the Uchiha are not aliens, and that they are actually just humans with mere traces of Otsutsuki blood, but in the grand scheme of things, when it comes to battle they are essentially the same as the aliens (or at least as Indra, and to a lesser extent Hagoromo and Kaguya). Their human genetics are irrelevant when it comes to their bloodline powers. That power comes solely from the lineage of Kaguya Otsutsuki (or more specifically from the chakara fruit which you chastise so much).
You people who make this argument say Uchiha > Otsutsuki as if they are two totally different things, but you are really just saying:
Descendants of this one enhanced Otsutsuki > other Otsutsukis
You chastise the Otsutsuki for having to use the chakara fruit, but the Uchiha's themselves wouldn't even exist without the chakara fruit (at least not in the way we know them). If Kaguya hadn't eaten that fruit (which you are considering an external power), then there would be no sharingan.
Without any external powers you ask? Well without any external powers the Uchiha don't exist, so the Otsutsuki wins by default.
Moral of the story: When people bring up the Otsutsuki in debate, nobody is taking about or cares about Otsutsukis outside of Kaguya's line (except for Momoshiki and Kinshiki). Therefore your point is moot.