When the ACA went into effect, three of the four doctors in the practice retired, and the admin staff went from 3 people (one part-time), to 12, with the remaining doctor selling his practice to a company that he then worked for.
Most doctors are owned by a hospital that is a part of a multi-state conglomerate. There are almost no private practices any more.
The amount of paperwork has tripled and ACA put the insurance companies firmly in the drivers seat. Do you have a medical condition that you have been getting treated for your whole life? Every couple of years now the insurance company has the power to force your doctor to justify continuing to treat you.