Upvote for unpopularity. I like the idea of not having to think about what to wear, but I don’t really care about the under-dressed/over-dressed part. I’m in a work place that went from a professional dress code to a business-casual dress code and holy shit was that great, just not having to care about what I was wearing, other than no ripped jeans or whatever, it’s just so nice. I sit at a desk all day, so nobody really ever sees what I’m wearing all day anyways, so whatever. Also:

1. Just getting people to wear a fucking mask during a global pandemic was enough for some people to want to go to civil war, good luck telling them what shirt and pants to wear (or that they should wear any in the first place),
2. I think even if uniforms were instituted, you’d still have members of society who would have to have something else. Politicians and/or military would get something else, just because. Then maybe you’d get other divisions getting added in, bosses at workplaces, religious folks, medical personnel, whatever, people will do anything to differentiate themselves from others, even if you try to start them out the same.

I feel like even in Star Trek, the different uniformed groups still probably talk shit about each other. Red shirts are obviously the big joke about being expendable, but then they probably still have informal green vs blue social groups popping up, the different departments are still going to be getting catty with each other over petty differences, even hundreds of years in the future. Then add in all these random fucking aliens from all over with way different standards, social taboos, and methods of communication, you’ll have alot of pissed off humans onboard starships hating almost everyone else they work with.