Quantum theory is not the problem but quantum woo is, i.e. nonsensical interpretations of quantum theory create problems by misleading people into wrong beliefs.
I never felt that the study of science was harmful beyond maybe to have wasted some time on studying in detail something which I will never use but that is unavoidable because as a student at university, I did not know in advance whether it will become eventually relevant.
I would like to sue the Catholic Church to give me back many hours of eager study of the Bible and other Christian texts and attending mass when I was a child and adolescent.
The harmful effect of being a Christian child was to distrust and refrain from pleasure and to socially isolate myself from peers who I considered to be mostly "sinners" by whom I did not want to get "tempted".
Luckily, I overcame this before the end of senior high school but I still feel the effect of insufficient socialization in my youth because I still need to make conscious efforts where others behave naturally without conscious effort.