Preventative care also consumes resources. A doctor can only perform 8-10 hours worked / (duration of preventative procedure) preventative procedures per day. The number of doctors is limited. Thus, the number of preventative procedures is limited.
Maybe doctors shouldn't be doing preventative care. Surely you don't need a Ph.D in medicine to perform and interpret blood tests, monitor blood pressure, take some measurements, and conduct an interview. If there are serious symptoms or something that doesn't respond properly to changes in diet, exercise, or simple medication, escalate to a doctor.
Specially trained nurses could be filling these roles much more cheaply, freeing up doctors' time for activities that require their training and experience.