My preferred variation of this is to make it an open question that leaves them in the position of authority, and assumes that they made a deliberate decision.
For example, instead of “Why aren’t you using StandardLib that does 90% of this?”, I would try “Could this be achieved with StandardLib? Seems like it would cover 90% of this”.
It’s satire, pointing the cognitive dissonance that allows people to recognize that fumes are deadly but never question the fact that our entire “modern” concept of city planning is built around constantly being in and around the machines that produce these fumes 24/7.