IMHO there are three clear causes for this trend: 1) US business fashion is increasingly casual. Ties, skirts, suits, coordinated outfits, scarves, leather soled shoes -- all are passe, even in button down East Coast Fortune 100 companies (other than for aspiring managers or those in banking/finance). 2) Color is passe. Shades of black and grey dominate wardrobes, especially in large cities. Thus fewer accessories ar…
All these explanations are rather complicated. I think the simplest explanation is the best: people don't have the free money to spend on clothing. This is evidenced by the following facts: 1) Wages have been stagnant 2) Cost of living has been increasing well beyond the stated 2% rate of inflation.
You'll need to support your claims about the second item. Saying it, does not make it so.
Real disposable income is at an all-time high. Personal consumption expenditures are at an all-time high.
https://fred.stlouisfed.org/series/PCE
https://fred.stlouisfed.org/series/DSPIC96
Americans are also spending less each year on soda. It's not because incomes are plunging 7% per year and they can't afford Coca Cola.