I think there are really 2 main barriers: interior dimensions and baking style
Is the inside large enough to bake the loaves you want? That depends on what you want to bake. They probably could accommodate 1 sandwich loaf in a tin, or even a focaccia on a half sheet pan or cake pan. So, yes, some breads would be feasible.
Hearth bread would be a different story. To make a proper hearth bread (boules, batards) at home, most people need to turn to a heavy, large thermal capacity vessel to bake in: Dutch oven, combo cooker, bowl covering a baking steel/stone, specialized bread baking vessel, etc. This is required to generate and trap large amounts of steam to help crust development and oven spring. If you can fit a 6 quart Dutch oven in your countertop toaster oven and heat it to 450 degrees, then it would probably work for that too, but it would have to be a pretty larger device for that.
They also make countertop ovens specifically for bread baking.
At the end of the day, it depends, mostly on what type of bread you want to bake. I, of little counter space, wouldn't buy one for with bread as it's intended purpose. If I already had one, I would definitely try tossing a tin loaf in it, especially when it is warm outside.