Every pending transaction in the mempool is a statement of intent. Bots read it before it settles and front-run what's worth front-running.
The contract calls ๐๐๐.๐ด๐ธ๐ข๐ฑ(๐ต๐ฐ๐ฌ๐ฆ๐ฏ๐๐ฏ, ๐ข๐ฎ๐ฐ๐ถ๐ฏ๐ต๐๐ฏ, ๐). That zero is 100% slippage tolerance. A frontrunner inflates the price, lets the swap settle, sells back at profit. A 10,000 USDC trade returns 1 ETH instead of 5.
๐ณ๐ฆ๐ฒ๐ถ๐ช๐ณ๐ฆ(๐ข๐ค๐ต๐ถ๐ข๐ญ๐๐ฎ๐ฐ๐ถ๐ฏ๐ต๐๐ถ๐ต >= ๐ฎ๐ช๐ฏ๐๐ฎ๐ฐ๐ถ๐ฏ๐ต๐๐ถ๐ต) lets the user set their worst acceptable price. If a bot moves the price outside that range, the swap reverts. The attacker burns gas for nothing.
The mempool stays public. Defense lives in the code, or it doesn't exist.