you also fail to understand the meaning of "dressing up nicely" ...
there are millions of combinations of good looking shirts, pants, boots etc. you won't look the same as others...
I work in an IT company as a test automation engineer and I also go to interviews with our HR.
We make enterprise level applications for international companies. Most projects are projects worth millions of dollars. All our developers, testers, consultants etc have daily interraction with our clients through video call and monthly we travel there or they travel here.
Excuse me, but even if you're a developer, looking like the ultimate ghetto hipster just won't cut it... if you don't show the minimum respect and dress properly when interacting with a client that spent millions of dollars in the projects, then I don't care how good you do your job, you're not getting hired.
Like I said, you can't appear dressed like garbage in a room full of clients and directors that all are decently dressed.