I think the culture as a whole keeps moving away from formality, which I don't find to be bad. Many times, formality is just an inauthentic pretense meant to make people in positions of power feel comfortable. Clothing is a form of self expression, which employers don't want because <reasons>.
fwiw, the phrase "shirt and tie" in American English is understood to be a button up shirt (I don't think most people specifically call this a "formal shirt") and tie. The "and tie" acts as a contextual modifier since it's rarely assumed someone would be wearing a tie with a t-shirt or something casual.
I've moved in the other direction in recent times, to some extent because I'm sick of the software engineer uniform. I wear a shirt (the kind with buttons) pretty much every day - some of which are made to measure and feature my own selection of colour and contrast colour, threads, collar type, cuffs and so on - and I often dress more formally at conferences (and sometimes on holiday, depending on what I'm doing) on my own time than I do at work.
"Clothing is a form of self expression, which employers don't want because <reasons>."
I wonder if my relatively formal attire in a sea of software engineer uniforms marks me out as one of these self-expressers - perhaps one day I'll be asked if I could please wear a t-shirt to work :)
That's just me; I like to look sharp. I expect that I am judged on that by some - look what he's wearing, I bet he can't even write code! - but as people here have implied in these very threads, if a company turns you down because you're well-dressed, you probably didn't want to to work there anyway!
fwiw, the phrase "shirt and tie" in American English is understood to be a button up shirt (I don't think most people specifically call this a "formal shirt") and tie. The "and tie" acts as a contextual modifier since it's rarely assumed someone would be wearing a tie with a t-shirt or something casual.