- Using Haskell means you can model your domain more precisely and have higher correctness guarantees.
- Using Rust means you get memory safety while maintaining the speed of C++, where the vast majority of vulnerabilities are memory safety issues.
- Using SQL means you can apply an optimizer on top of what is essentially relational algebra over tables.
In all of these cases, a less effective tool could be used, yes. But "it's just a tool" doesn't capture the fact that tools do solve domain-specific issues, and OP is not wrong to seek an employer who acknowledges the value of Haskell has to add.