By definition philosophy has come to refer to the study of things that cannot be resolved by empirical inquiry. So, every time human advancements have ACTUALLY allowed us to answer a question, it ceases to be the realm of philosophy.

For instance, Plato and other Ancient Greek philosophers theorized about the basic building blocks of matter—what their shapes and natures were. That question has become one of physics.

That’s why philosophy is referred to as the Mother of the Sciences.

This hardly makes philosophy worthy of your description as lacking “tangible results.”