A component of this is fear of liability in a highly-litigious environment. Nobody wants to be the one who told someone to wait and see instead of going to the

A component of this is fear of liability in a highly-litigious environment. Nobody wants to be the one who told someone to wait and see instead of going to the ER, only to have the person wind up dying or suffering serious harm. This is further exacerbated by the limited safety nets in the US–even people who would on principle deign to sue others who tried to help them in a time of bad luck may find that a lawsuit is the only way they'll be able to maintain a decent lifestyle after the loss of a partner, or with a newfound need for long-term care. One more layer is the fact that doctors are so overbooked. Many people cannot reasonably get appointments with their family doctor (if they have one) on short notice, so some things that, in the past, might have been a "wait-til-morning then call the GP to drop in same-day" are now "GP is booked three months out, guess we're going to the hospital".