Earlier quoted context omitted.
With Haskell, you can be more precise in expressing what you want.
That wouldn’t make a program written in it “more” correct.
We might be coming from different backgrounds and hence not immediately understand each other, but, at least in Haskell if the types are precise in the sense that you can't construct invalid values, then using such types will make your programs more correct.
For example, if you want a program from a number to HTML, then if the HTML type is a syntax tree type of all valid HTML rather than wrapper around string, then filtering LLM output by that type will make it more correct than a string wrapper kind of type (as with the latter, any program generated by the LLM which returns a string and wraps it into HTML will do).
The actual use cases might not go as extreme as the above, but the idea is that the "tighter" your type is, the better it is on pruning LLM outputs from invalid programs.