For every certainty, there’s always the possibility of an alternative solution. The choices you make today are really just guesses about how things typically work, not necessarily how they should.
Playing devil’s advocate forces deeper thinking and greater innovation. That is, deliberately going in the opposite direction gouges out the truth. Experimenting with doubt solidifies supposed certainty.
The dialectic exists to create better answers, not finite solutions. If we all just knew, we wouldn’t be trying so hard to survive.