There will be no foundations at all ~ and the money and other accumulated wealth will be recycled instantly into productive enterprise.
Your solution is a just different flavor of tyranny. People must be free to do with their own money as they please (Matthew 20:15) The problem is not that people give their money away, but that we set up a tax-exempt vehicle that allows their money to be used in perpetuity to muck about in society and politics.
A sufficiently endowed tax-exempt foundation has eternal life only because we choose to exempt it from taxation of its earnings. Now it is a simple truth that corporations cannot be taxed. Either the customer or the shareholder is taxed in reality. However, a foundation has no customers or shareholders to pass taxation on to. That is the special deal that was granted to those who were wealthy enough to use this provision of the tax code.