He's not an extrovert but that doesn't mean he doesn't want friends. He doesn't want to be the center of attention, speaking loudly during break times. He values smaller groups where he can actually think and speak; it's why his conversations with the FMC and his sister go so smoothly. He can suffer his way through HS alone but a bit of bitter medicine to help him find connections that he'd actually enjoy would help him.
99% of people want friends, and no you aren't that 1%. People don't want to be alone, they want to express their ideas and be heard. Even MangaDex and Crunchyroll have comment sections. 🤷♂️