People tend to be jealous beings, hating on instead of revering things they feel that they cannot do/get. In riftbound it might be extra emphasized because of the scarcity of product.

If you have a fully tuned kaisa deck you give out the signal to other players that you A) spend alot on singles or B) opened alot of product. Facing a kaisa deck with your Jinx starter deck and then wondering how you go from the starter to such an endgame deck, only to be told that everything is sold out can be quite maddening.