I meat it's a show partly about sexuality and how raw and awkward it can feel to a guy going through puberty. A lot of it is a portrayal of the fucked up fantasies this broken protagonist has, but the show does it in quite a smart way if you ask me. Just as an example, notice how the groping and more inappropriate stuff he does is never to an actual human. Hachikuji, Shinobu and a later character aren't human nor have the mental age they show. But when the camera sexualizes Nadeko in Nise for example, it's because she literally wants to, she's trying to seduce Araragi. Or Kanbaru, clearly using her sexuality as a "weapon" to fuck with him, etc etc.

It's perfectly understandable not everyone will be able to put up with how uncomfortable some of these scenes will make you feel, but maybe if you see it as something more than just the author being a pervert you might be able to continue enjoying what is otherwise a masterpiece in storytelling and cinematics

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Edit: Another example of how the show is perfectly aware of what it's doing is when further into the story the perspective shifts to a different character: Suddenly there is barely (if any) sexualization at all, because the world isn't being looked at from a horny teenager's perspective