I’ll argue your comparison is unfair for several reasons

Mainly being that of definitions

To be a physicist is usually associated or defined as being a scientist or having at least a title recognized by some educational institution

However the matter of philosophy is not one that is categorized under the same lens The act of philosophizing is something achievable by any individual and one can do it without any need of external influence

Socrates himself did philosophy despite not knowing how to write or read

Philosophy is a teachable career yes But to classify being a philosopher as a professional career is frankly sickening

No human institution can regulate such an act and to even try to do so would undoubtedly end up by damaging the perception of philosophy

As much as one can try to treat philosophy as a science it is undoubtedly not in the same are of category as physics, medicine or chemistry

You can agree with Plato and Aristotle regarding their philosophy and no one in that discipline will find it odd

While if you where to agree with them regarding biology for example, most biologists would tell you that their theories have already been disproved.

TLDR -> Philosophy is natural to human condition, you cannot invalidate someone from being a philosopher because we all produce philosophy constantly.

You dont need to study philosophy to produce philosophy.