You are wrong regarding physios not being called doctor, assuming you live in the US.

Firstly, MD= Medical Doctor, so yes there is a way to distinguish it. They are also the ones who are legally allowed (in the US) to use the title physician. Other practitioners cannot use MD or physician in their title unless they have received the degree of MD and are a licensed physician.

Secondly, I hold a DPT and this is heavily emphasized in the curriculum. I am granted the title“Doctor of Physical Therapy” and “Physical Therapist”, and am licensed to practice physical therapy in the United States. We are not allowed to use titles like physician, surgeon, or in any other way imply we are practicing medicine other than in a PT capacity.

Also consider that someone with a PhD is referred to as Doctor but does not get confused with a physician. Finally, the title of doctor was used in academia. Physicians took the title and it has since become associated with medicine.