Shirts - as well as clothing - have become more tailored or trimmer the last few years - as you have probably noticed. Jackets fit more closely to the body and are shorter than they have been in the past. Trousers are flat front these days and have a lower rise to them (sitting more on the hips than at the waist). The leg is narrower which lend itself to a shorter break (i.e. further from the ground). A full break does not work well with a narrower leg as it causes the pant to gather rather than drape. All the more reason to wear eye-catching socks from Falke or Paul Smith! Shirts are no different. With a trimmer jacket and trouser, a more fitted shirt is appropriate.
I have to say that more fitted clothing is more flattering - on all body types - whether you are little or big. It makes one look more fit regardless of their shape. A baggy shirt on a smaller man makes him look sickly or wimpy. On a bigger gentleman it makes him look even bigger. Obviously my eye has adjusted to (and prefers) more tailored clothing. I don't know how I will react when pleats come back in fashion (some 20 years from now if they do) or over sized, Armani-esque clothing. I imagine it will come back in a different way than it was in the 1980s but I still think there are certain styles of clothing that are timeless - and that is a properly fitting, close to the body, jacket, pant and shirt.
We still have fuller shirts for the guy that doesn't like how cotton feels against the skin - but we are seeing more and more guys prefer a more fitted shirt. Aside from in-stock offerings, we can do custom shirts with Kiton and Finamore (both handmade shirts from Napoli) and our own brand. One of the shirt makers we use starts at $195 and has a delivery of 4 weeks. This shirt maker is fully custom. We take several body measurements then determine the fit and collar that is best for you. Next time you are in - have a look at the swatches.
Coolster in Florence (image from The Sartorialist) wearing a fitted suit and shirt. Notice the narrow leg of the pant and how the shirt pulls slightly at the chest - that is how it should fit - don't let this bother you.