I stopped getting any care at a large hospital near me's outpatient office because they had a bad habit of just sending bills to collections before my insurance responded to them, and then not updating anything once they did, so I'd get a debt collector notice and call the hospital, and they'd say "oh you paid that in full, you shouldn't be getting a notice" "well you should probably tell that to the debt collector".

Over and over again.

So if those started showing up on my credit report eventually, it'd be a significant impact, even though I was not involved in any failure to pay. Fortunately, they never did, but for many people, that's not true.