never had to go to the ER personally, however, i did do an internship in one during my junior year of college. what i can say is that, yes, people do wait, but at least people get treated in a timely fashion. the more severe cases go first, but most, if not all, people are seen by doctors.
lots of people go to the ER for little things, a cough or a headache. those people are lucky that they are seen for colds or headaches because they have insurance. imagine now that there is universal health care. imagine how many more people will be in the ER over little matters. that takes up doctor time that other people with more severe problems need.