It is involved because there is slack on the system in the form of downtime, and it figured out that if it just buys up all the doctor's offices, makes the doctors rush through the cases, and keeps them busy seeing patients every working minute, the practice and it's owners will make way more money.
Quality of care will decline, but unless the doctor is actively doing surgery, or something else risky, whatever money they lose due to the decline in quality will be more than offset by grinding through patients quicker.
It's almost impossible to sue a doctor for malpractice in Texas, yet the exact same problem with PE is happening there, too.
Vets are another example where this is happening - and again, it's not because of frequent $XYZ,000 malpractice settlements. Anything that's not billable hours seeing patients is considered to be damage by the system, and capitalism tries to route around it.