"Often people who dismiss philosophy end up going over the same ground philosophers trode hundreds or thousands of years ago."

Really? When I look at Aquinas or Plato or Aristotle, I see people mostly asking questions that we no longer care about because we have found better ways of dealing with the issues that made those questions worth thinking about.

Scholastic discourse about the Bible or angels makes much less sense when you have a historical-critical context to explain how it emerged in the way that it did, and a canon of contemporaneous secular works to make sense of what was going on in their world at the time.

Philosophical atomism is irrelevant once you've studied modern physics and chemistry.

The notion that we have Platonic a priori knowledge looks pretty silly without a great deal of massaging as we learn more about the mechanism of brain development.

Also, not all new perspectives on the world have value. Continental philosophy and post-modernism are to philosophy what mid-20th century art music is to music composition. It is a rabbit hole that a whole generation of academics got sucked into and wasted their time on. It turned out that the future of worthwhile music was elsewhere, in people like Elvis and the Beatles and rappers and Nashville studios and Motown artists and ressurrections of the greats of the classical and romantic periods in new contexts, and the tone poems and dissonant musics and other academic experiements of that era were just garbage. They lost sight of what music was for, just as the continental philosophers and post-modernist philosophers lost sight of what philosophy was for.

The language in impenatrable because they have nothing to say. I know what it is like to read academic literature, for example, in the sciences or economics, that is impenetrable because it is necessarily so, but that isn't it. People who use sophisticated jargon when it is really necessary are also capable of speaking much more clearly about the essence of what is going on - people like Richard Feynman. But, our modern day philosophical sophisticates are known to no one but each other and are not adding to large understanding. Instead, all of the other disciplines are busy purging themselves of all that dreck so that they can get back on solid ground.