Words break if you push them too hard.
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Philosophy is just knowledge of what various philosophers have said over different things over the years. In many cases, people have forgotten who discovered what they discovered.
Western philosophy begins with Socrates, Platon and Aristotle. Works from their predecessors is referenced in fragments of their later works. Their fields were speculative cosmology that occasionally dives into analysis.
This changed particularly with Aristotle. There started to be a lot more analysis. Platón and Aristotle might have been influenced by progress in math after mathematicians showed that analysis led to more conclusive results than making up stories. Aristotle is credited to a huge percentage of newly discovered territory in one lifetime, proving how new this kind of thinking was.
But then Aristotle proposes that there are two kinds of theoretical knowledge: practically useful and not. Since people interested in theoretical knowledge are interested in it for its own sake rather than for practical need, it must be more noble. He sets as his goal in Metaphysics to explore knowledge that has no use. No one really notices when he takes on vaguely understood questions and ends up getting lost in words.
His mistake was to confuse motive and result. People who seek a deep understanding of a subject are often driven by curiosity rather than need, but that ⇏ that their findings are useless. It is very valuable in practice to have deep understanding of what you're doing. Being able to solve complex mathematical problems by deducing shortcuts from simpler one is better than relying on formulas you don't understand.
This makes theoretical knowledge prestigious and is the root of specific curiousness in smart people. Aristotle had contradictory aims with Metaphysics: exploring abstract ideas guided by the assumption that they were useless.
Platon and Aristotle were impressive and naive. Ancient philosophers were similarly naive. In particular, they didn't understand that concepts we use in everyday life are fragile. "I" is an example of this (you = bunch of cells). Words work well enough in everyday life, but they start to break if you push them too hard. This resulted in most philosophical debates being driven by confusion over words. Do you have free will? Define "free."
When something is hard to understand, it's hard to distinguish if it's because the writer was unclear in his mind or because the ideas represented are too complex, and writing about big ideas in an unclear way only produces what seems to be good writing.
Proof is how little effect some words can have: no one is a different person or does anything different as a result of reading Aristotle's Metaphysics.
Since their work became the map of future generations, they were off the wrong path too and things remained the same for ≈2000 years until philosophers in Europe became confident enough to (sometimes) treat Aristotle's work as a catalog of mistakes.
But Aristotle's explanation of the ultimate goal of philosophy in Book A of the Metaphysics –to aim to find the most general of general principles– implies that philosophy should have a goal.
Perhaps truly pursuing Aristotle's original goal of discovering the most general truths, is still worth pursuing today. But unlike in Metaphysics, we should do it because general truths are useful.
Ideas like this seem to be ideal for philosophy: general observations that cause people who understand them to behave differently.
Civilization always seems old, because it's always the oldest it's ever been. Although philosophy is considered to be a 2500 year-old field, for much of that time philosophers weren't doing much more that commenting on Plato or Aristotle while the next invading army arrived. Original ideas were hopelessly tangled with religion, meaning philosophy didn't free itself until only a couple hundred years ago. In a sense, the field is still at the first step.