What is negative sum in this example?
A has mined some coins which B buys for 100 USD. Now A has less than 100 USD because the transaction costed something and B has 0 USD. Together they already lost money. This will only get worse. Let's say B can convince C to buy his coin for 1000 USD from, say, an interest free bank loan. Aye, B has 1000 USD minus transaction fee so they made a profit but C has -1000 USD. Altogether they are short on money.
Even here, both users are short USD, but it is not a "negative sum" system as the users gain some positive value by having the payment processor transfer and secure their funds. If the only metric is how much USD a buyer has left, every visit to the bakery would be a negative sum game.
In the above example, PayPal and Wise are User C. In a permissionless blockchain, User A and B can both also opt to be validators and receive these protocol rewards, so there may not even be a User C that extracts rent on each transaction.
When a limited supply token is burned, the total supply is reduced, and assuming that does not decrease the demand, then the value will diffuse to all token holders. If 75% of all PayPal or Wise fees were burned such that all users of PayPal had their account slightly appreciate in value whenever there is significant transactional volume in the network, a lot of users would be pretty into that.
Besides, this is just one way. Bitcoin does not burn fees, so it’s much more like the PayPal and Wise approach, no money leaving circulation.