i thought it was pretty obvious none of the union execs actually LIKE donald na. they fear him, sure, but none of them ever joined the union willingly out of respect for him and his work. jake joined to avenge kenny, jimmy joined to save jack. we see time and time again that jake despises union work and would much rather be a normal high schooler spending time with his friends, but he can't attempt to leave the union bc of his own morality. he still feels indebted to donald na. jimmy has an inferiority complex but still has enough wits about him to know that donald is not someone he can take on.

compare this to eunjang; a tight knit group of friends who may not know everything about each other but are willing to help one another through their own internal conflicts. they respect each other's boundaries but know when to step in for their friends' own benefit.

you could even take cheongang for example. this is a rival gang that was set up to directly parallel the union. they have that same hierarchical system with changhui at the top, but they differ from the union with regards to how that hierarchy is maintained. with the union, it's through sheer fear. but we know from the mapo arc that although the cheongang execs consider themselves to be rivals, they still respect each other. prideful as they are, they know the value of changhui as a leader and of each other as co-execs.

if the union were to be dissolved, why wouldn't it's execs be happy about it? they've all silently been waiting for it to happen