I love a nice waistcoat, and I too prefer mine to be more fitted. I'm always on the lookout for any that fit well and that are affordable. (So often the ones that I like I find are over $125 which makes the search challenging.)
The issue of how "modern" dress is worn so loosely today is one that I'm constantly frustrated by. I've never understood, nor liked the "gangsta" influence on men's style. Pants below the butt - underwear showing, or shirts and tees so big that they hang to or below the knees. And just overall general sloppiness not becoming of any gentleman. Again, I digress and find myself delving into the psychology of clothing...
I'm all for comfort, but I just don't see these clothes as flattering for any body type. I'm reminded of a previous thread here on X discussing the merits of overdressing vs. underdressing. I'd much rather stand out for looking "too good" than for looking like I don't care.
To get back on track, it was mentioned that men of yore were perhaps smaller than they are today. While that's true to an extent, we have all seen pictorial examples of men of girth throughout history. And, it has also been said, any man of means would have had his clothes made to measure. "Proper" fit has become somewhat subjective it would seem. In this respect, I find myself decidedly old school. Altering one's own items is a great idea, if you have the skill. Unfortunately, I do not, so I must rely on my tailor.
So much for a "quick reply!" :-)