Postmodernism has ruined many things.
It’s ruined philosophy by replacing useful and life changing (or at least interesting) teachings with nihilistic nonsense.
It’s ruined architecture. Where civilizations of old built beautiful, awe-inspiring buildings that stood for thousands of years, modern buildings are monstrosities that serve more to oppress than enlighten and uplift, and without constant maintenance would crumble to the ground in about a century.
Modern popular music is a disaster. With few exceptions, it gets simpler, louder, cruder, and more repetitive with every decade. This isn’t just conjecture: there have been studies that show this. Every 8 years music get louder by one decibel, the chords are simpler, the lyrics are increasingly shallow, meaningless, and degenerate.
And of course, modern “art” is an aesthetic abomination. We’ve all seen the obscene, uninspired, talent-less garbage that is pushed by the purveyors of art as “good”. Sometimes the art is literally garbage.
The common philosophical foundation that unites all of these “creative” disciplines that have instead become repetitive, boring, and ugly, is that beauty is subjective. It really isn’t. Sure, people have different aesthetic preferences, but few can stand in an ancient cathedral built 1,000 years ago and not be inspired by the intricate work, and most are not inspired, uplifted, or even impressed by the laziness and incompetence of modern art.
Whether these are the symptoms of a civilization in decline, or on the other hand it’s cause, is hard to say. What’s certain is the feedback loop isn’t positive.
The less meaningful art a civilization produces, and the shorter the art’s expected lifespan (modern architecture won’t last more than a century), the less pride we have that our civilization is even worth protecting. I mean, who wants to protect their culture from foreign invaders, whether physical or in the form of bad ideas, if its buildings look like this?
But outside the circle jerk of galleries, museums, and art schools, there is real work being done. Art is still alive in some video games and movies. Even website design. Anywhere where artists can appeal directly to consumers in a market, instead of being filtered and stifled by stuffy establishment critics, art has continued to inspire and elevate.
Hope is not lost, you just have to look in new places.