When I started work ** years ago suits were mandatory office attire. Over the years they gradually became less necessary unless you were in sales. You can spot a used car salesman from a mile away.
I have rarely worn a suit outside of work except for weddings and funerals and now I doubt if I have one that would fit me any more.
I had someone working for me a few years ago who always wore a suit even to go on holiday. Strange people programmers.