In medicine and other technology, the "first mover" advantage goes away when a superior product comes out. In the case of medications, what doctor is going to prescribe an older, less safe, less effective medication, when a newer, better, safer, and probably cheaper one comes out?

Sometimes a platform will win even though the professionals think it's less good. VHS beat out Betamax, which video professionals viewed as superior -- but it was more expensive and fussier than VHS (so there's a question as to whether it was really better for the TYPICAL consumer).

In the case of drugs -- it's good to have multiple drugs approved for a disease, because some people are allergic to some drugs, or don't respond well to them. But the FUD we can anticipate is groundless. When it comes to people's health, a drug that is simply better is going to be the standard of care.