If no one can overcome bias, does that make all their professional output useless? Do you want to buy "philosophers are crap" at the expense of "everyone is crap"?

No, for just the reason I pointed out. Mathematicians, "hard" scientists, engineers, etc. all have objective measures of correctness. They converge towards truth (according to their formal model). They can and do disprove wrong, biased results. And they certainly can't fall prey to a presentation bias that makes them give different answers to the same, simple, highly formalized question. If such a thing happened, and if they cared about the question, they would arrive at the correct answer.

That's the consistency. What about the correctness?

Consistency is more important than correctness. If you believe you theory is right, you may be wrong, and if you discover this (because it makes wrong predictions) you can fix it. But if you accept inconsistent predictions from your theory, you can never fix it.

Which would make mathematicians the logical choice to solve all real world problems....if only real world problems were as explicitly and unambiguous statable, as free indeterminism , as fee of incomplete information and mess, as math problems.

A problem, or area of study, may require a lot more knowledge than that of simple logic. But it shouldn't ever be contrary to simple logic.