A three-piece suit with a waistcoat seems to be standard everyday wear, even for many working men. In the modern age, even upper-echelon professionals only get THAT dressy for special occasions or days. Aside from seeming like an effort in an age where we're told the average person was poorer in real terms and technology made washing clothes a more laborious process, it begs the question of whether they dressed like that in hot summers too.
What you first need to remember is that a suit today is only required for more formal business or occasions. Therefore, demand is very low. The trade of making them is much more specialized than, say, making jeans. Whereas, before the mid-20th century just about everyone owned a suit. Demand was higher, more mass-production of suits was available. Even the fabrics that make up suits were more readily available. The wool industry has shrunk drastically over the last 50 years. This means that today we need to find someone who has a rare skill and uses rare materials to make something they have a limited number of customers for. Therefore, it needs to be pricier.
A suit in the 1930s could be had from a catalogue for $15-$20 easily. Some were as cheap as $7. That'd be about $60-75 today. Not all suits were good quality, but on average far more were. They were meant to last a long time, and were built from the right materials with the right re-inforcements to do so. And washing isn't a big concern when it comes to suits. I really hope you never wash your suit. You might take it to be dry cleaned if it's worn often or you stain it, but generally it's the shirt and underwear you put between you and it that gets laundered.
Another factor to remember is that if you buy a suit at age 22, around the time you're entering the business world, why would you stop using that particular suit? Today we might because it no longer fits. Occasionally it might be due to some minor damage. Or perhaps the style is a little out. All of these things could be taken care of by any tailor. Something much harder to find today than back then and something we always forget about. Our general reaction to clothing that has these problems is to get rid of it and get a new one- they didn't do that.
As for why we no longer wear suits all the time today, it's simply the evolution of fashion. We are just far more casual today in our dress and it shows in the quality and treatment of our clothing.
Oh, and adding on, for summer there are summer weight wools or linens. Light colors are worn, so the sun doesn't heat them up, but the skin is kept covered so it doesn't get burnt. And if you sweat, it doesn't show in a suit like it would in a t-shirt. But that undershirt worn under the suit and regular shirt soaks up all of the sweat and can be bleached to get clean or simply replaced when it's too far gone. Less clothing isn't necessarily better in the summer, just look at traditional dress worn by nomadic people in the desert- covered completely in loose, breathable fabrics. They wouldn't survive in a polyester bikini.
Do you have an example of poor people wearing nice clothes being photographed back then?
Daguerreotypes were very expensive. If your family could afford one, you could afford nice clothes. You also wore your best clothes, as this was something you might do once our twice in your life.
I'm sure there's a few anomalies of rich enthusiasts who photographed the poor. Were they well dressed though?
Also, fashion was different back then. Labor was cheaper, so were suites.
hi, you may be interested in this earlier post; more from /u/colevintage and links to a few more
I'd like to see the photos you mean. I think though chances are you are looking at photos of a member of the growing middle class.