With women's fashion, it's an easy one with pockets and for some probably less sheer/thin or tight-fitting clothing depending on their preferences, but for men...?
What would you like to see done differently in men's fashion?
This is already the case in every field with maybe the exception of law, diplomatic situations, and formal government (parliamentry sittings etc.). Hell in tech it's all jeans and t-shirts. I keep a white shirt, tie, and jacket in my office in case I have to go the legislature. Other than that I haven't worn one for work in years.
Should be just more acceptable to wear what ever you feel like. It is in big cities or if you confident, but would be nice if people felt less pressure.
Business casual that is suitable for a hot summer day. Right now the best a man can do is slacks, a good shirt with the sleeves rolled up, and boat shoes.