Stories that have the MC seclude themselves and avoid human contact in pursuit of knowledge,power, you name it.
https://www.royalroad.com/fiction/36049/the-primal-hunter - the MC just grinds solo, the whole story is about him grinding. The author doesn't put in the effort to write in meaningful social interaction.
Frankly, I believe it is lazy writing. I stopped reading it after 200+ chapters when the MC had an opportunity to pass on good information that he found out, but didn't for no reason. This wasn't the first time either. The MC is owns a city in a very might-makes-right new world, but he just doesn't care. He knows a lot of critical information that he has no thought on sharing because "he's a loner". Interacting with people interferes with his grinding. But that's just my opinion. This novel is very popular on RR. The writer makes $20K per month from just this novel on Patreon.