Nothing effective about self-diagnosis. Quick and easy yes, but not effective. Most things that are worth diagnosing require a visit to a clinic. No doctor is going to lose a job because people are self-diagnosing using the internet.
They gonna get more work due to results of self diagnosis from the internet.
It wouldn't be "Ah! It's lupus." It would be "I need the results of such-and-such tests to make a differential diagnosis."