I did say "mandated", as in what airlines are permitted to advertise. In Canada, for example, airline weren't advertising prices with taxes and fees included, which would sometime result in $500 price difference between advertised price and effective price. The regulators got involved and changed that practice. I am suggesting that we should be getting the government to be forcing an equivalent change when it comes to carry-on.
So when you say "It's nice that most of the cheap brokers now include all fees", this was forced on the airlines and not something they did out of the kindness of their corporate hearts.
How many people really travel with no carry on? 10%-20% of travellers?