Human bias. People tend to treat you favorably when you dress a bit nicely. You don’t have to over-do it, but you also don’t want to appear “rough”. I’ve travelled both ways, and can tell you for a fact, you get hassled more if you look like you just rolled out of bed, as opposed to someone who’s at least trying to look presentable.

I always put on pants when I go out. It’s the decent thing to do

I never understood why not. Dressing up “nicely” doesn’t need to be uncomfortable at all. If the clothes fit well and are suitable for the occasion and location you can be comfortable and be dressed nicely.

What I never understood is people going out in pjama’s or sportwear while acting like those are the only comfy clothes in the world and the rest of the people are making themselves have a worse time. Be it at airports/planes or elsewhere. Putting on decent pants take 2 seconds and can be just as comfy, so time and comfort aren’t really much of an excuse. People should invest in good basics for day to day use, you’ll earn it back in daily comfort.

But also, some people simply enjoy looking a certain way. Even for less comfortable clothes, that enjoyment can be bigger than the discomfort making it worth it to them. It’s not always about having a reason.

To rule out the google ap ypu could try in a different wifi network like a library.

There is a simple reason you haven’t considered.

I want to bring my suit on the trip, and I don’t want to crush it into a bag, because it’ll wrinkle.

Habit. And I’ve become good at finding outfits that look nice and are just as comfortable as ones that look more casual.

My company was very old school and had a dress code for all stupid situations, including travel on business. Also, fly in and fly out meetings are a thing. In the 90’s they wouldn’t let you sit in first class - before points aligned status were a thing, travel enough and you would get bumped up often when in a suit over others.

Because I come from a family of pilots and the free F&F tickets came with the stipulation that we dressed very nice. I grew up with that and the habit stuck.

They probably dress nicely most of the time.

Wearing a shirt and nice trouser helps my business traveller persona dont want to explain an immigration officer why I wear work clothe and steel toe booth for a business meeting.

Anyway, I have a business meeting, need a suit and will be back the next day, so I am rather wearing my business suit, rather than taking a checked in luggage

I’d say… why not?

One reason among several is tradition. Air travel used to be the domain of the wealthy, at a time when the wealthy seldom left the house in super-casual or working-class attire.

By dressing nicely you show respect for other people.