I went to the ER in the US for an infected gallbladder full of stones, it was so bad I had to be hospitalized for almost a week. I was in the ER waiting room in the fetal position for literally hours after a nurse took my vitals before a doctor saw me, there were a couple other people in the waiting room. I nearly died. Over $20k bill after insurance.

I’ve also gone to the same ER with relatively mild UTI, I peed blood and fainted from the sight but otherwise didn’t really need the ER. They saw me immediately, and it was very busy.

Triage is a thing, whether they do it properly is another thing.