Putting aside the often absurd costs for a moment...
Many ERs are also severely overburdened, understaffed, and overcrowded often with very high ratios of non-emergency patients to emergency patients. This creates huge wait times for patients and puts significant stress on medical staff.
Talk to your friends, family, coworkers, almost everyone has a bad story to share, whether about absurd wait times, wild costs, billing screw-ups, insurance debacles...
And talk to your doctors and nurses too, they are just as frustrated.