Se*ual content and aesthetics. Overall it is the same genre, modern BL with a lot NC scenes. There is a scene in Wandee Goodday where main leads are watching a scene on television that includes main characters form Only Friends. Even covers are similar aesthetics.
They're both thai BL and have the "friends with benefits" trope
idk much about wandee's story bc it's still airing, but i think if you like this trope you'll like both series :)
