The difference is you need ice skates to skate on ice, you need baseball gloves to protect your hands, and while you don’t explicitly need running shoes you generally benefit from wearing a proper shoe for running if you are competing at a certain level. There is a function behind every one of your other examples.

What fucking pants you wear during chess is utterly meaningless unless you specifically want to create an air of superiority over people who do not dress “formally” (whatever that means). It is merely a means to exclude people who do not meet an arbitrary standard of appearance, which historically has just been a way to oppress lower socioeconomic classes and minorities. Fuck meaningless dress codes and props to him for standing his ground

This really isn’t a high bar

Just an unnecessary one, yes.

what do you think athletes spend on running shoes, baseball gloves and ice skates?

Last I checked, chess isn’t played from the trousers. Though maybe that would make it more fun, I don’t know.

dress codes almost always specifically exist to exclude the poor

Equating sports equipment to a dress code is incredibly disingenuous and you know it.

Literally every professional sports has some form of equipment requirement and chess is probably one of the cheapest.

For real? You realize that those requirements are utilitarian, right? And if there are any relics leftover from old days, or bullshit rules that aren’t utilitarian, then they’re just as dumb as the OP situation.

Jeans are normal trousers.

In inpatient psych, street clothes are a common dress code. There’s some variation between facilities, but clean, untorn, no novelty tshirts, somewhat modest, no camou, are items you will often see in the line up. I started going to a new facility and failed to read this in detail due to habit and personal inertia. That’s on me. I showed up at this facility for over two years running wearing basic: black/dark non tshirt shirt, long cardigan (open front “jumper”, maybe, to you), and new grade looking deep indigo jeans. Black boots. Some variation, but that’s a normal street clothes look for me at work. You know how it is, some of us dress like we live in a type of street clothes uniform because we dislike shopping, multiples of the same items.

No one noticed I was wearing jeans for over two years, or if they did, they said nothing. Then one day, a new house supervisor saw me stooped over a computer out on unit at the nurses station, documenting before I was about to head out, and awkwardly approached to first clarify that I was wearing jeans and then to again, awkwardly, tell me jeans are not allowed at the facility.

Pause, two workers look at my legs, one says “Those are jeans?” Leans in, peers closely, then says “I guess they are.”

My point is, enforcement of non-egregious dress code violations are a choice. Those choices often rest with single individuals.

In neither case do these jeans disrupt the environment. In neither case were people harmed by the wearing of jeans. Nor are the trousers of choice tools required for standardizing the way a task/sport is completed. Offensive? Maybe to a prior generation in a “that is just not how things are done!” kind of way that is primarily fed by generational inertia.

For my part, unless I wanted to start wearing skirts, leggings (not appropriate for work imo), or wedding attendance level clothing, this change required me to go shopping.

Given how professional poker players dress, I’m not sure what the “sport” application of a uniform in chess is for, beyond “this is just how we do things”inertia.

Normal trousers are jeans not the other way around. And jeans are the pants of the people.