Back in my day... clothes were a bit more functional, and made of natural materials. There were a few synthetics available but didn't really take off until later. Look at a movie or magazine from that time; everything was cotton, wool, or a few other natural fibers. And they were mostly made by hand, in this country.
Today, most clothing is made overseas, because of labor costs. In 1949, the clothes we wore in this country were made in this country. There were clothing factories and tailors in most medium to large cities.
Styles change, due to whims, new ideas, and of course to make older clothing obsolete so new stuff can be sold. We look at some of the older styles and chuckle, but this will be the fate eventually of what we call hip now. Rather than chasing for the latest and greatest, it makes more sense to go with timeless fashions that never go out of style, like Brooks Brothers.
Another thing is general neatness vs sloppiness. Look at a photo from 1949; everyone is sharply dressed, and the men all wore hats. Contrast this with today - if men wear headgear at all, it is usually a baseball cap worn backwards, and with writing on it. Good fashion abhors writing of any kind. When I see somebody wearing clothing with a company name in large letter, I always wonder how much they are getting paid.
And when did it become fashionable to wear pants that are slit at the knees? This is fairly recent, and quite disturbing to many. My parents came up through the Great Depression, when people often had few different clothes and took very good care of them; a rip or tear was a thing of shame and would be fixed promptly. Now people pay hundreds of dollars for pre-ripped pants. And people pay extra for pre-slit! Ah, the vagaries of fashion!