TIES! Think professional, even if the same work can be done by a casual person in a T-shirt.

On the other hand, ugly men people think are morally weird too, like they cannot be relied on. Undisciplined... Aesthetics do matter, even if people claim otherwise to protect their PR

Cognitive dissonance yet again - brain hates when pro personal bad, or when messy person great.

How much should I care about aesthetics over function?
Aesthetics worksfor initial marketing or first impressions. Only. The backend might have to be good too. But a job interview - if you lose the first chance you lose it all so wear a tie.
Ties exist for that reason.