Of course you personally don't care what kind of insurance a patient has while you're treating them. But that's not what people mean when they say "level/standard of care provided by your insurance company."

Some insurance companies may have a very limited number of "in network" treatment centers and patients can get stuck with costs for going out of network. If the health insurance is especially bad, they may have unreasonably low negotiated rates for out of network services and the patient will be forced to cover the difference (and this can legally go beyond out-of-pocket maximums)

If someone has a rare disease or complicated injury their insurance may not cover access to the best specialists. For example, instead of seeing a pediatric heart surgeon who specializes their baby's specific deformity they may get access to a more general pediatric surgeon who operates on a range of parts and doesn't do hearts often.

Bad insurance companies may frequently deny claims ("experimental," "not medically necessary," "not an emergency," etc) Even if insurance can't legally deny a claim and would lose a lawsuit, the hospital may be unwilling to perform the treatment (perfectly legal if the patient is stable) if the insurance company just says they'll deny it. The hospital can't take the risk that they'll get stuck with the bill if the patient's family can't pay.

I have really fantastic health insurance right now. I've had it for three years, my husband and I combined have seen half a dozen specialists for various things, an emergency room visit, a couple urgent care visits. I've literally NEVER seen a bill other than a co-pay. Seriously. Even infertility treatments, never paid for anything.

I don't even pick specialists based on my insurance's "directory" I just get the most highly-recommended one in the area from my doctors or I do research online and pick the best available. They always accept my insurance, never been an issue. I just checked, and only a couple of them accept Medicaid. My PCP's office does not accept Medicaid. They do same-day and next-day appointments, they have a selection of teas and comfortable sofas in the waiting room (and a stack of actual cotton hand towels in the bathroom!), everyone's friendly and well-paid, but only for those with expensive health insurance.

Heck, we're even 100% covered for medical emergencies while traveling abroad (including transport, air ambulance) -- Medicare doesn't even pretend to do that!

So yes, the level of care people get is VASTLY different, depending on their insurance. As long as I have the choice (knock on wood), I would never ever want to have a baby with Medicaid.