Clothes make the man -- uncomfortable
Has there ever been a more cumbersome and more determinedly uncomfortable set of garments? Almost every part of the body is enclosed, usually fairly tightly. Trousers, shoes, and shirts all have to be hauled on separately, often with some effort -- has there ever been a greater absurdity than the shoehorn? -- and if it doesn't take effort, they're probably too loose to look right or stay in place properly. Shirts have to be buttoned up (why did zippers never catch on for shirts as they did for trousers or jackets?) and many shoes still need to be secured by tying laces into a peculiar and silly-looking sort of bow-knot. The whole ensemble is fussy, awkward, and over-complicated.
(Yes, I know Victorian-era clothing was even worse, but that's essentially an earlier version of the same culture and clothing tradition. I'm grateful for the simplification that has happened since then, such as it is.)
After all that, you're not comfortable. A change of posture as simple as sitting down can cause constriction of the groin, waist, or even armpits. If it's warm, no comforting breeze can reach most of you. Why are smelly feet so common a problem as to be an occasional staple of jokes? That's what a day's worth of tightly-trapped sweat will do. Absorbent socks mitigate the problem, at the price of one more tight, silly-looking item to deal with when dressing.
The fact that modern clothes are fairly tight, and have to be in order to look right or stay on properly, means that you have to buy new versions of everything if you gain or lose a substantial amount of weight -- often a non-trivial expense.
And don't even get me started on the necktie. This utterly non-functional symbol of conformity has always put me in mind of a leash. It's one more otherwise-useless knot to learn, it takes some practice to get it to look right, and it requires a fairly tight collar -- one more point of constriction. It is, thank goodness, seemingly on the way out. During the last Presidential election I recall seeing both Obama and Romney at at least some campaign events without ties, and nowadays, if you're in a typical office and you see a man wearing a tie, it's usually either the president of the company or a temp worker on his first day on the job.
What alternatives can history suggest? As is so often the case, we could learn a thing or two from the ancient Greeks. The clothing depicted in Greek art or statues may look elaborate, but in fact most garments in that culture were variations on a simple large sheet wrapped very loosely around the body below the armpits, with the front and back pulled up and pinned together over one or both shoulders. For fancier effects one could add sleeves, or a sort of sash over one shoulder, across the opposite hip, and up the back to the shoulder again and pinned in place, or even a cape. In most cases getting dressed or undressed took probably a couple of minutes. Contrary to modern impressions, these simple clothes were usually brilliantly colored, in contrast to the drab palette favored for male clothing today.