Why does my friend who seems unattractive to me keep dating women way out of his league?

I have a friend who, by most conventional standards, wouldn’t be seen as attractive. He’s overweight, unkempt, dresses however he wants, and has very niche hobbies like weird or disturbing movies and games, which he talks about openly even with people he’s just met.

He jokes a lot about how autisitc he is and honestly, yeah you can tell. He does drugs and is upfront about it, he dropped out of college, and doesn’t really care about his job. He works in IT but treats it as just a paycheck. What surprises me is that he’s also incredibly intelligent, like even talking about things he has just heard about he can put together more of it than even people who are familiar with the subject, but he’s super lazy and doesn’t seem motivated in anything but talking about weird anime games or movies.

Despite all that, his partners are always incredibly attractive and often highly educated. His current girlfriend is doing her doctorate. Lovely girl his age who honestly seems like she could date anyone, and she seems completely in love with him. I know from an ex of his he was always a great boyfriend but they didn't work out due to stuff on her side. I might just be jealous, but I look at this guy and wonder how he keeps doing it? Is being tall that much of a cheat code or has he just mastered not giving a fuck and that confidence carries him? I feel bad thinking about him this way but he really does seem to have some kind of magic?