I thought you were a karate instructor…
My mom (born 1943, Camden, NJ) dressed comfortably most of the time when she wasn’t at work, and was not shy about wearing cutoff shorts, halter tops, and Birkenstocks most of the time. But as late as the 1980s and 1990s, if we were ever going into downtown Chicago (to go to a museum or shopping, etc.), she refused to wear pants at all. Maybe she wouldn’t be wearing heels, but she would always wear at least a skirt and some nice non-heel shoes.
This.
And not only was there back then a desire to not look like a working stiff, but today, there has arisen a goal not to look like a pampered weakling/clueless status seeker*.
A hundred or so years ago, even white-collar people had to deal with more physical labor than we do today. Horses are more work than a car (and require a helluva lot more skill). And even if you had a car, it didn’t have power steering, and you may have had to start it by hand-crank. (And speaking of horses, walking across a street exposed a pedestrian to uglier pollution than most of us today ever deal with. Someone free of manure on their shoes obviously had assistance with their transport. People didn’t need to worry about looking like pampered weaklings - hell, that was sort of the dream.)
Today, our surroundings are much cleaner, and it’s much more common to not need to exert ourselves physically for much of our day. So wearing clothes that make it clear we aren’t performing physical labor is less of a distinction. (And, there’s less distinction not having shit on our shoes.)
In many workplace settings, if two white collar workers are of equal competence, the one who is (or just looks) more comfortable performing physical labor will likely enjoy higher status. As noted above, casual dress can also convey higher confidence in one’s abilities - no need to kiss up.**
*The Tom Haverford character on ‘Parks and Rec’ is a good personification of what is low status like this. He’s obsessed with “dressing for success”, and is often shown to be comically physically weak. You didn’t have characters like that on ‘The Donna Reed Show’.
**When people tell me that you’re supposed to dress for the job you want, not the one you have, I claim that the job I want is retired Nobel laureate. They can dress however the hell they want!