I think this is what is missing from most modern philosophy, that makes it so easy to dismiss as useless. In Ancient Greece most of the philosophers were strong people, that had personally done great things, or endured incredible hardships with the aid of their philosophy, and these real world tests stood as evidence of its value.
People strove to become a Stoic because the people they admired most in life had been guided by it.
I think philosophy ideas can and do have the ability to prove their own utility in the real world. To the extent that modern philosophy has mostly failed to do so, is probably because it is either wrong and/or useless, OR is just not developed far enough to get to that point.