They definitely are not god enough - I speak from personal experience.
On one occasion an NHS hospital dentist reduced my DD to tears with his irritable manner - and his rudeness was witnessed by another dentist in the same room. When I made a complaint, both colluded and denied it ever happened. What could I do?
When I complained about my broken foot treatment - which has left me with a permanent avoidable disability - again the medics ganged up to deny everything, in spite of the fact that a specialist at an orthopaedic hospital had eventually made the right diagnosis. What could I do?
The system is a nonsense. The only virtue that I could see is that the complaints would be on record and if others occurred regarding the same doctors might serve to ring alarm bells.