can someone please explain to me why the kardashians are still relevant when no one, myself included, agrees that they're still relevant
You are not the all encompassing being who controls the fashionable interests for everybody else.
I don't like the thick cement mixers either, but the fact of the matter is that other people find them interesting; for many it's that "car crash effect", while others may just have a genuine interest in them. We all need stuff to take our time on this planet, and deep down we all have one "dumb" thing we really enjoy.