7. Massage can be done by anyone.
Of course it can. Just like singing, drawing, playing football or playing politics. The question is quality of the result.
A masseur is, at a minimum, a profession, and ideally a talent.
It never occurs to anyone to go to an exhibition of paintings by people who can’t draw, or to a concert by a singer who can’t sing. And this is often the case with massages.
Without knowing the anatomy and physiology of the body, massage can be harmful. One of the simplest examples is that only a professional masseur knows that during a massage blood must be driven to the heart, not from the heart.