the definition of self-taught: having knowledge or skills acquired by one's own efforts without formal instruction
I think you're engaging in some weird goal-post moving. The phrase exists to highlight the difference between "i had someone else tell me all the things I should know and let them give me that knowledge" (e.g. college or a boot camp) and "i went out and found resources and did experiments so that I could learn what to do without that guidance". It is not "i discovered everything for myself by first assuming some principles and then rebuilding the whole field for myself".
I think you're engaging in some weird goal-post moving. The phrase exists to highlight the difference between "i had someone else tell me all the things I should know and let them give me that knowledge" (e.g. college or a boot camp) and "i went out and found resources and did experiments so that I could learn what to do without that guidance". It is not "i discovered everything for myself by first assuming some principles and then rebuilding the whole field for myself".