[Serious] Generally speaking, is philosophy a worthwhile subject of study?

[Angrboda]

The philosophy of science is basically a form of epistemology. Any time you think about why or how science discovers or outlines reality, you're doing philosophy. Science without philosophy is impotent.

(And most folks would say that physicalism is metaphysics, not something that can be tested.)

ETA: Come to think of it, if biology and chemistry can be reduced to physics, then there is only one science, physics. But then, that requires thinking about reduction, which is philosophy.