Were Newton's laws superseded by quantum mechanics?

Yes, within the quantum domain. This mean when we start looking at scales at an atomic level, Newton's laws do not apply and quantum mechanical effects take place. However, on bigger scales such as where us humans operate day to day life like going on a run or driving a car; Classical mechanics takes place where Newton's laws operate.

Somewhat, but not practically speaking. Through Quantum mechanics, more questions can be answered about the behavior of very small things and quantities, in a realm where newtonian mechanics breaks down. However, the information and results we get from the application of newton's laws' to the macroscopic world we humans experience, remain sufficiently accurate as to be just as good as any other theory, while being significantly simpler to both apply and teach