Hisoka isn't sexually attracted to little boys. He's sexually attracted to strong fighters. Just because the two main protagonists are little boys doesn't mean--

Yeah, fuck that, can't do it. Yeah, Hisoka is creepy as fuck. But he's supposed to be creepy as fuck. He, at least, is never supposed to get audience sympathy or trust. He's a creepy groomer and is treated as such by the narrative.

It's better than Mushoku Tensei (Jobless Reincarnation) where the protagonist is a pedophile, gets ostracized in his original life for being one, and then after reincarnating proceeds to indulge his desires with little to no pushback in the series. People find him relatable and misunderstood. That's 100x more egregious than anything Hisoka did.