I’m not sure if there’s any field where everyone is qualified. It seems there is no perfect method for objective qualification, without letting idiots slip through the cracks.
One of the better methods is to have a supervisor watch them in practice, but how do you qualify a supervisor? The whole cycle repeats again
There are some really stupid doctors, scientists, electricians, architects and welders, all of which are occupations where incompetence can have dire consequences.
There are recent cases of flawed scientific papers, used as guidance for procedures (ex: surgery), and causing potentially thousands of deaths.
https://youtu.be/HTlKGKaOQPY?si=2oXTn6UdR0Fuxtgj
Cases like this is what feeds anti science movements and conspiracies. In many circumstances “science” shouldn’t be trusted when there is no line between flawed science and good science.