International trips require the coat and hat in summer. Its hot AF wearing that…

Delta doesn’t…. After a 8+ hour flight… the Deltoids look like crap.. the “I slept in my clothes and haven’t been home in 24h” look.

United pilots look professional. So there is that.

The other reason is …. If a crew gets sideways with a foreign government, looking professional is highly advantageous.

This has been happening for 100 years, there is nothing new here.