Newtonian physics is an assumption of QM. (It's traditionally called the "classical limit.") QM would be nearly useless if 300 year old physics weren't correct.

Newtonian physics is an assumption of QM. (It's traditionally called the "classical limit.") QM would be nearly useless if 300 year old physics weren't correct. It's just that 300 year old physics is not a complete picture of reality, which may have been something its developer's improperly assumed.