Pros have been going to narrower bars over the last few years, to the point where, for the first time, the UCI has had to mandate a minimum width (no bars narrower than 35 cm outside to outside are allowed; they also established a limit to how far inward the brake levers can be canted, to keep riders from achieving even narrower positions). If they can remain competitive during 5-hour stages through the Alps, I would guess they're not having much trouble breathing.

Another formerly unquestioned standard is being supplanted: after many decades when almost all pro riders used crank arms that were 170 mm or longer, the two most recent Tour de France winners have been using shorter ones: Pogacar is on 165-mm cranks, and Vingegaard is riding, or at least testing, 150 mm.