Sorry, this post got long. Summary - insurance is a huge problem. Regulations add cost, but not as much. Private equity is also ruining healthcare.
Insurance and billing is huge. A long time ago, doctors just said "a regular appointment is X dollars, if you need this procedure it's Y dollars, etc." Now, no one knows what things cost because everyone's insurance is different. And insurance companies will use any excuse to cut payments to doctors. I knew a team of 3 nurses at one hospital that worked full time just fighting insurance companies denials of ER visits. They told me on average, they would be able to get 1 million dollars back per month from insurance, with their biggest month being 3 million.
Another thing insurance does is prior authorizations. They make it incredibly difficult for doctors to prescribe certain medications, order certain tests, and such. The doctors have to get on the phone or write a letter to insurance requesting approval. And it's supposed to be another doctor on the other end, in the same specialty. However frequently it's nurses or other non physicians reviewing the requests. Some insurances also have a policy of default denial, forcing the physician to resubmit, at which point they'll actually review it. If you're trying to see enough patients to make a profit, this eats into your time to see patients, or your personal time.
The ACA made it illegal for doctors to own hospitals, so many healthcare facilities have very highly paid healthcare administrators at the top that make quite a bit more than the physicians. And like most large corporations, they make it difficult for the small guy to run a business. So lots of private practices are getting purchased by private equity. There are cases where private equity purchases hospitals, then sells the land to a realestate firm, who then lease the land back to the hospital at a significantly higher rate, which saddles the hospital with debt.
There are regulations, but I don't think they're that huge. Certain things cost money, such as electronic medical records. These really are the future (present now). Most physicians prefer paper because it's faster, and cheaper to have a filing cabinet than to pay for an electronic system subscription. But electronic does allow it to be sent easier to other physicians, and to export to a patient when they move. Lots of problems with interoperability within systems, as they all want you to stay with them, so they make it hard to migrate.
In the case of the ER bill above, most of the cost is fake money. The hospital bills insurance huge amounts of money in hopes that it might get a few hundred out of it. Then the ER doctor is not employed by the hospital, so they bill separately (or the company they work for does). In general, they have to bill everyone the same, otherwise they're committing insurance fraud. But they get different reimbursement rates from different insurances. And you can negotiate a cash pay.
Everyone thinks doctors are getting rich, and some are. Most are certainly better off than 90% of Americans. But there are certain specialties (like pediatrics) that do not make much. Depending on where they work, and whether they accept medicaid, they could be making less than 6 figures. Physician income has actually decreased, when you account for inflation.
There's a lot of hatred towards the medical community right now, thanks to COVID. And everyone's access to google is making everyone a doctor. But there is seriously a lot of pressure for young people to decide not to go to med school. When you think about it, after college, it's an additional 7 years minimum to be an indepdnently practicing physician. During those 7 years you're spending 4 years living off loans and acquiring debt. And then 3+ years of living off a resident salary of 55-70k, depending on which part of the country you live. They have to move for medical school, and then for residency, often without a ton of say in where they get to be a resident. Physicians often delay starting a family, purchasing a home, saving for retirement, and life in general until they're done with residency. If the stress is going to increase, and the payoff decrease, we're just going to see a greater decline in physicians.
