To think the power imbalance in between them at that time, one was trying everything to put his rookie grp from a bankrupt company out their by all means & other guy from a established grp from a big company using his position to humiliate him.
It's not a ego issue but pure evil
remember when Jungkook was telling Jimin about the letter Namjoon wrote for him during the showcase🥹🥹
“he didn't know how to treat me because I was the youngest, and that he felt a lot of things while watching me, that I looked the coolest that day”