zahavasdad: Can you refer us to a picture of any of the above wearing jeans at an occasion where one is expected to be formally dressed? Jeans are a cheap but study undressy fabric. They are and were designed for doing physical work. It’s what you wear when you ride horse, not when you ride in a motorcade. It’s what you wear at Camp David when only family and staff are around – not what you wear to a state dinner in honor of foreign dignitaries.
Most frum Jews will dress semi-formally (respectfully) at all times, and denim is by definition and informal non-dress fabric.