I bake various types of bread on a weekly basis, and have never seen a recipe that doesn't require sugar or honey. I'm pretty confident it's needed to fuel the yeast for the rising process vs the flour alone.
There are plenty of bread recipes that require no sweetener, and it's definitely not needed for yeast to develop.
A lot of the packaged supermarket bread has additives to keep it fresher longer, one of which is sugar. Go either a little upmarket or to the baked-in-store section and you'll find some without it.
Bread has been staple food for millennia. For most of that time, sugar was rare, expensive or totally unavailable.