'REBEL'--yes, that 'I'll wear what I like' and 'You can't tell me what to wear' and 'dressing well is so 19th century' is a rather trite refrain in this thread. All the faux rebels!
Oddly enough, though, none of the "I'll wear what I like" folks are telling you NOT to "dress better," if you prefer to dress more formally.
Fine, OK, who cares if they are turned away from a bar or wedding or restaurant or club because they aren't dressed appropriately.
Never been turned away from any of the above. Nor do I think I'm likely to.
I know enough to dress up for the rare trip to a formal restaurant; the vast majority of restaurants these days are casual dining where, frankly, nobody cares what you wear beyond "no shoes, no shirt, no service."
I've never heard of someone being turned away from a bar; there are some that get very formal crowds, and you might get an odd look going into them in very casual clothing, but so what? You're equally likely to get an odd look for showing up in formal clothes in a divey, casual place.
Clubs, well, not my scene. My guess is, though, that for the handful I've gone to if you show up in a business suit and tie you're going to stand out negatively more than merely unfashionable or ill-fitting casual clothing.
Weddings are, by definition, special occasions. Even there, while many are formal, not all are.
Meanwhile,
work is the thing many people will most often dress up for, and AFAICT, in my industry places that require formal dress are the dinosaurs.
Someone wearing inappropriate clothes in any cabin of a plane (the list of inappropriate clothes seen lately is very long)
Inappropriate clothing on what is in essence mass transit is very limited.
looks clueless, out-of-it, slobby, and antisocial.
To the contrary, judging strangers on their clothing when you've got no business with them is the sign of a snob. Indeed, to a large extent unless "dressing well" is part of their professional capacity, judging people on it in a professional setting is largely the sign of a simple, superficial mind or a snob as well. Socially, well, there's no accounting for taste.
I'm rather reminded of the notion that you should judge a person on their watch. It seems rather odd, since it's jewelry with an original purpose that is now largely obsolete (who doesn't carry a phone?.)
Social comportment: being well-groomed, discreet, well put-together, respectful of others, etc, are all part of a civilized society. Some people don't want to do that, they reject the concept, or simply don't have a clue how to dress or any sense of style.
Conflating things that are purely a matter of appearance with things that actually impact other people has nothing to do with a civilized society.