You can make this exact same argument about the constitution and the courts. Why did the founding fathers wear wigs and fancy shoes? Why do court justices wear those fancy black robes? Why are there so many laws and rules and amendments? It’s because rules evolve over time as new situations arise. The Catholic Church has been around for 2000 years so of course it would be full of various stuff that has evolved. It’s weird if you to dismiss it instead of wonder why it came to be - it didn’t just spontaneously appear in one second.