When you don't spend the time and money on preventative care as a society, you end up spending much, much more on emergency care. I feel like this has been quantitatively demonstrated again and again, but it's somehow still a political football.
I am aware of a number of studies which looked for a negative correlation between preventative care spending and overall healthcare spending, but all (of which I am aware) failed to find it.
When you allow lobbying this is the kind of issue that becomes rampant.
Due to freedom of movement around the US, population wide benefits such as healthcare, housing, and in some ways, education, require federal level solutions.
Otherwise, someone is going to end up being the sucker that foots the (giant) bill for everyone else.
On the federal level, there is quite a bit of gridlock, so what we have is an intractable problem at the non federal level where it is every man/neighborhood/city/county/state/hospital for themselves.
It's not so much a minor thing turned into an emergency (that is a problem of course) but rather the patient has no other venue for minor needs without money or insurance.
If triage were able to turn away non-emergency cases legally it would gradually change, but for people with more time than money the ER basically ensures you'll be seen.