> the union can do exactly what you wish it to do.

ICE can also do "exactly what you wish it to do", so why do people complain about it so much and want it gone when it does what people want?

The answer is that even democratic institutions easily get corrupted and hard to deal with. US unions seem to be very prone to this for some reason, both union leaders and corporate lobbyists wants the unions to be corrupt so I don't see that changing either. Many people would gladly take a salary penalty if it lets them avoid yet another corrupt bureaucracy above them.