It’s weird that Aragorn has a reputation for being a Loner™ when every time the heroes go to a new place they find out Aragorn Has Friends There. If you could theoretically have friends there, then Aragorn Has Friends There
They meet Aragorn in Bree, turns out he’s Friends with Gandalf, then makes Friends with the hobbits, then they arrive at Rivendell and what a twist he’s also Friends with the Rivendell elves! especially Arwen and Elrond! There’s an elf from Mirkwood in their fellowship who was already his Friend, but he also quickly becomes Friends with the dwarf from Ered Luin who hates that elf’s guts. Boromir of Gondor initially WANTS to hate him but within a couple weeks he’s calling Aragorn his brother. The Fellowship arrives at Lorien and oh Aragorn didn’t bring it up but he’s also Good Friends with Galadriel and Haldir and Celeborn and all them too! They travel to Rohan and Aragorn’s like “oh yeah I didn’t mention it before but I’m Friends with the people of Rohan, I knew King Theoden as a kid, and–”. He even makes Friends with his horse
Aragorn tries to befriend everyone, from a 3-foot tall hobbit who’s not yet an adult to an elf-queen-sorceress older than the moon. He doesn’t seem grim/lonely because he’s friendless, he seems grim and lonely because he has so many friends, in so many places, that he’s always missing someone