One problem is an obsession with comfort. People in the past dressed and built to present a sense of uplifting refinement and dignity, not just to be as comfortable as possible. That has been lost, and so you see obese buffoons waddlng about in cookie monster pajama pants
The bigger problem, and the one that led to that being swallowed hook, line, and sinker by much of society, is prole drift: the tendency of the proclivities and habits of the underclass to, in an egalitarian democracy, gradually become the habits and proclivities of everyone. Paul Fussell drew attention to this in his book Class in the 80s, and it has gotten far worse since then
This killed any societal spirit that would trend towards beauty, rather than mere gaudiness or incitement to lust. For one, the underclass certainly puts comfort before dignity, and so we're getting a full dose of that. But it's everything else too, paticularly the general apathy about anything "nice" and a total lack of sense regarding manners, decorum, cultivation, and so on
Who would build a cathedral in a land of cargo shorts and sandals or tank tops and sweatpants? Who would build a restaurant panelled with oak or with a marble floor if the patrons will wear in their ball caps and eat a steak with their hands? Who is going to get out the silver and china when they're worried their guest will pocket a teaspoon? No one. And so it's not done, and all the little things that made life beautiful are replaced with what is easy, efficient, and cheap
Why is nothing beautiful anymore? Why does nothing feel like this?