Now, with the addition of lycra to fabrics making them stretchy, the breeches can be snugger. Especially since most riders are not riding in real rough territory. Trust me when I say that today's breeches won't last a moment in real rough terrain. It will just be a bunch of pulls.
So yes, yesterday's breeches were baggy because of fabric and function. However, they DID rub. I know this well.....Todays fabrics are so comfortable with the stretch, you almost feel like you have very little on (if you know what I mean....)