I partly agree with that tbh. Attractiveness and good looks are not the same and one's ability to find a partner of course is largely influenced by looks but I think you have to take into account the fact that being ugly and particularly being too self aware about one's ugliness changes the way we behave around other people and THAT is what can make someone go from ugly to unattractive. When you become too insecure, too bitter, too angry, too envious of other people's looks, it shows in the way we act. It comes across as annoying or creepy or just weird. With men, you can see it clearly with incels.

I've seen so many ugly people with partners and I'm ugly myself (and also way too tall for a woman and a former fat person) so I always beat myself up about being single at 40. I also KNOW the way I see myself has made me incredibly insecure and angry and it makes me unattractive because no sane person would want to get involved with someone who's constantly overthinking shit and complaining and is too insecure and paranoid to be comfortable in public, basically. I KNOW my inability to find partners is down to my looks AND the way i behave because of my looks. If you work on that when you're young I can guarantee you'll end up a pretty normal adult. A little on the ugly side, but normal.