Man, what?
I defy you to find cosmic horror from the last....let's say, 80 years....that wasn't directly or indirectly influenced by Lovecraft.
Hell, I defy you to find sci-fi, horror, or fantasy from that same time frame, not influenced by him. Damn near every writer, director, artist, etc. cites him as a major influence. From Del Toro to King.
Of course you ain't gotta know him....that was my point. The shyt he popularized and/or invented damn near 100 years ago is now the tropes in that sub-genre. Not to mention, most of his works are public domain which is why people feel so comfortable "expanding" on his connected universe.
And yeah, I'm familiar with who influenced him....but none of them....not Bierce, Dunsany, Chambers, Machen....
none of them....are as influential as Lovecraft. Because he took pieces of, probably 20 authors, who didn't have a unified vision and created what we now know as cosmic horror. The only peer he has on that level is Poe, who obviously isn't similar, at all.
So yeah....saying Lovecraft didn't invent cosmic horror would be like saying NWA/Ice-T didn't invest gangsta rap. Technically true but nobody after them is citing Schoolly D.
Fred.