With the corporate arrangement, you are paying those additional 7 percentage points of tax for a big privilege, granted by the government: limited personal liability for the debts, losses, or contracts engaged by the company. That's a legal bonus you simply don't get when acting as a proprietor.
You can just form an LLC and get the same limited liability while being taxed as an individual sole proprietor. What you write was an issue in some jurisdictions forty or fifty years ago, but there were limited partnerships even then to get limited liability.
With the corporate arrangement, you are paying those additional 7 percentage points of tax for a big privilege, granted by the government: limited personal liability for the debts, losses, or contracts engaged by the company. That's a legal bonus you simply don't get when acting as a proprietor.