I think you sorted things into three types of medicine:

[ pseudo, alternative, modern/mainstream ]

I think he believes that most things you put into the alternative category have already been mostly studied; those being not proved or disproved to work.

I think the that some issue here comes from the fact that conspiracy theorists / other (for lack of an agreed upon modifier) medicine gurus may have used the argument that some medicines aren’t proven to be bad yet as a way to give them legitimacy.

Whether or not other medicine is good for you should be be studied and determined to be medicine or not. Until then we can’t say anything about its efficacy. But there can be carry on effects: protein powder was found to have heavy metals, is protein powder good? Maybe in certain circumstances, but concentrating a given substance can have unintended consequences when not properly analyzed.