Is IAS good after MBBS?

Yes, definitely. UPSC Civil Service Examination just need a graduation. And MBBS will serve that purpose. All the best.

Of course, there are many who are like that, let MBBS be a fall back option.

Yes, qualifying for the IAS is good, especially after MBBS. This is because you have the option to pursue civil services as a doctor, and not just any other aspirant. There are certain requirements you have to fulfill before applying for the UPSC civil services exam like age, years of study etc. To