>>212134982As much as I enjoy him, he wasn't any of that.
Clark Ashton Smith wrote about similar themes and wrote arguably better, hence why he was way more prominent back in their days. Not to mention that Lovecraft himself took heavy inspirations from Dunsany and Poe.
Majority of his writing deals with the very fundamental fear of unknown, nothing that much original in it too. "Cosmic Horror" thing only relevant in like a handful of his tales. And he loved to spice things up with a good old monster scare here and there, in typical pulpy fashion.
Lovecraft wasn't ahead of his time, on contrary, he was a product of his time and wrote accordingly with the cultural zeitgeist of his epoch. Things like Temple are satire of that period's political climate, and stuff like Cold Air simply isn't that impressive due to modern cultural trends.
Lovecraft wasn't super popular back in his day simply because he was a mediocre writer with mediocre success (he wasn't really as downtrodden as people tend to imagine).