In California it's gotten so ridiculous that almost every city has its own sales tax [0]. This leads to some mild arbitrage where if I live on the border of LA County, I can go over to any city in Orange/Ventura/San Bernardino County and immediately save 3% off the purchase price.
To expect every taxpayer to keep track of where they've purchased items and pay a use tax so that taxes are going to the right places should not be on the burden of the tax payer. I'm a happy taxpayer and willingly will do so to fund our civic services and public goods, but not when the sale never occurred in the area where I purchased the item. People will find and exploit loopholes the minute they are revealed.
California (and some other states) have already gotten around this by requiring new cars registered to pay a tax adjustment if it was previously registered from another state. I don't think the state government just has the time or resources to do that for all purchases.