answer:No, it’s very true. Men’s fasion, especially formal/businesswear, hasn’t changed a great deal since the 1920s. And the ubiquitous jeans-and-plaid-shirt combination would have been as acceptable 150 years ago as it is today. What changes most I think, is not the garments themselves but the occasions it’s acceptable to wear them. We happily wear a nice white cotton t-shirt in public now, whereas seventy years ago people would wonder why you were walking around town in just your underwear. The 1950s were the big sea-change for men’s fashion in Europe and America; previous to that, pretty much the only thing acceptable to wear in public would be a suit, or at least a dress shirt and smart slacks. Or whatever work-wear was appropriate to your profession. But along with the emerging of pop-culture, more casual wear became acceptable. My current dresscode for the office (smart plain pants, polo shirt of any colour) would once have been acceptable only on the golf course. The rest of it is just details. A suit made in 1920 would look different from one made in 1970 or one made today but only because of changes to such things as the fabric used, the size of the lapels, placement of buttons and pockets or the overall fit. It’s still basically the same suit.