Why do oc shippers do this?

I'm sure other shippers do it as well but I've noticed this happening more with oc shippers. They somehow feel the need to insinuate that other ships aren’t as good as theirs or toxic to elevate their own ships. This person was saying that a popular tiktok song belongs to their ship like countless others also haven’t used this song for their oc/canon canon/canon pairings as well. Tbf it might have been meant as a joke but I see some people doing these sort of 'jokes' over and over again so it gets kimda annoying. It's probably not that serious but I would like to hear some other opinions on this.