In the past, decoration was much more expensive than plain objects. A craftsman would have to spend extra time adding this (e.g., paint some pattern on a plate). So such objects would be a true signal of your wealth. Nowadays, decorated stuff costs almost the same to produce. It's now only an indication that you have a really old tast for style.

There might be even a reverse factor: fake products. In my eyes, golden stuff always looks cheap. If someone in my bubble would suddenly wear a golden watch, we'd make fun why they got it from some guy on the street for five bucks.