Agreed. For someone whose experience of suits is the ill-fitting obligation for the occasional wedding or funeral, it will be shocking and unbelievable to read that a custom cut dress shirt is more comfortable than a t-shirt, and suit pants, soft and silk lined, more comfortable than jeans.
It might be shocking to realize that not all body types fit well into a suit, regardless of how well tailored it is. I used to be tall and lanky, great for a suit. Then age happened, and now I'm much more round that beanpole. Nothing fits well, and I've tried custom shirts etc. I just look like a well dressed, round person. I'm not more comfortable at all, in fact the opposite.
Plop me in a pair of shorts with a t-shirt or better, a hoodie and I feel great.
Interesting. I've been told that the suit is so ubiquitous over history and nationalities, because it flatters older and portly gentlemen more than other items.
I would say in the last generation, we’ve really had a ton of incredible new textiles be developed. Spandex and its blends in particular has added a lot of comfort in clothing, and wasn’t even that widespread ~15 years ago in comparison to the degree it is now.