The other thing that sales taxes prevent is using stores to create implicit transport requests: if I sell something at one location for 12.35 and buy it at another for 12.36, that’s offering 0.01 per unit to transport it (as well as putting market orders at those prices. But a 1% sales tax would mean that the smallest amount to offer to pay for shipping intrinsically would have to be .13, of which the shipper gets .01.
Shipping contracts exist but need to be interacted with each time they happen.
On White-Tiger we hence have a transporter profession (if you didn't take any skills) that is exempt from sales tax.
But noone there would transport anything for a single cent. Can also use a contract for that, given the government will in any case want to tax that service in some way.
On the other hand our sales tax is between 10 and 20 % mostly, depending on the goods, so we're far off 1%.