You’re never going to totally eliminate tax evasion, no matter what system you choose.
But the fact is that the vast majority of retail transactions take place in legitimate retail stores, like the big boxes, etc. Such businesses have little to gain, and everything to lose, from fudging on something as basic as a simple sales tax.
On a (perhaps) related issue, I have always had a nagging concern about how the tax system has turned employers and retailers into tax collectors for the government. Sometimes I wonder what would happen if employers, for example, were not forced into the role of tax collector, and the government simply sent everyone a tax bill on January 31st, payable on April 15th, based on their reported income. My guess is that most people would be shocked to see, in a lump sum, what their tax burden really is, and then think about how not to pay the bill.