“so they should tax every year on that which people have earned, paid taxes on, and own in their own right.”
In some way they are doing that now: Real Estate and personal property taxes.
They do it to business as well.
In Florida and Kentucky (probably many other states also) you have to pay a tax on accounts receivable. Yep, a tax on what you have not even been paid.
Keep in mind also that AR are NOT all profit. A large portion of AR goes to paying the cost of being in business.
Think of it. Your cost of the product and providing it may be 90¢ of every dollar you get paid, yet the state makes you pay tax on your expenses and profit, then taxes your profit again when you get paid. Nice racket.
PS: You also pay an annual tax on your equipment - over and over. Your desks, computers etc ad nauseum.