Food fight was shared with 6 other characters, board game was with the whole team, combat skirts was .3 seconds long with a high-five. And if “board game” is one of the only scenes you can think of for them in this show that can deal with monsters and tragic backstories and magic and fighting evil for the sake of good, that says a ton. Out of all that, Ruby and Weiss have “board game”.
Whereas Blake and Yang have had a very deep heart-to-heart for half an episode, Sun and Blake got an entire season together to bond, Jaune and Pyrrha - don’t even get me started, Ren and Nora had childhood together as did Ruby and Yang, Yang and Weiss also had a deep conversation and heart-to-heart.
Ruby and Weiss have nothing. No SIGNIFICANT scene alone together for longer than 5 seconds. They don’t have a heart-to-heart beyond volume 1 when Weiss said maybe Ruby wasn’t so bad, but even after that she still continued to be nasty towards her. They haven’t had a scene to be amiable- to be friends - with each other in years. There is no content to potentially build a song around for them.
People can name exact episodes and scenes for other characters “That Blake/Yang scene” and “That Yang/Weiss scene” and “that Jaune/Pyrrha scene”. But what is the “Ruby/Weiss scene?” There is none.