The ED is a downstream effect of upstream problems
People upstream (mostly politicians, to some extent hospitals and especially insurance companies) need to stay comfy and to do that they throw all their problems down into the ED well. No matter the funding, no matter the staffing, you're responsible for what walks through that door.
The other elephant in the room is the overall mindset. We are increasingly an acute-care country. Preventative medicine is almost entirely immaterial to much of this country. Why monitor for diabetes if I can just come to you in DKA?
Edit for more soapboxing:
Two problems are going to make this worse soon
Expansion of ****ty medicare advantage programs, which is already problematic as hospitals realize how ****ty they are and kick them out
Medicaid cuts will be complete by 2028. This means your poor population, who already have problems seeking care, will exclusively come to you now. Also, unlike their clinics, you are required to see them but you won't get paid. But you can still get sued if you F up