There was a time when this term had meaning. The fact was that the only jobs that pulled in six figures easy were jobs like lawyer or doctor; you wore a suit or a lab coat to work. It was a fairly formal work place. The fact was that if a lawyer came (or still does come) to work at his firm in a t-shirt and shorts he would probably be either fired or reprimanded. The places that allowed casual clothing in an office only allowed it on a certain day maybe once a month but we don't live in a world where this term is still applicable.
Here is an extremely successful person at work.
That is Larry Wall, A very successful computer programmer, He created Perl, and what Perl is happens to be unimportant but the fact is that Larry Wall is worth well over five hundred million dollars is rather important. The fact is most successful lawyers aren't worth that much. Yet who wears the suit and tie and who wears a t-shirt and shorts when they work and quite frankly Tech Company Employees are far more important to this country than any lawyer one makes money on misery, the other builds computers, software and robots.
My Father works for Oracle corporation.
and if you haven't heard of them. The Chances that you are a user of one of their products is astronomically high considering you are on a computer or phone. You know the software Java, thats them. That is one of their products and they are one of the biggest of the Tech Giants. However most of their rather important jobs aren't done by people in suits and ties but rather dressed like this
I'm getting a lot of use out of him today but he illustrates my point. Engineers and programmers often come to work in a t-shirt and Jeans. sometimes the software engineers come in at eleven randomly and work till seven instead of five. Why do they do that, because they can. My Dads good friend works from home. He commutes fifteen feet from his bed and sometimes works in his PJs and that is becoming increasingly common in the modern age.
The fact is while Dress for Success used to actually have meaning, now successful people dress in a whole lot of different ways.