Compared to modern brakes, no, as you'd expect the originals are not that good.
If your truck has stock or similar stovebolt engine the original brakes in good shape are perfectly adequate.
If you change engine and gearing to go fast the original brakes will feel inadequate.
I do have 4.10 gears in my GMC and the original brakes seem fine for 55 mph.
Still plan your stops as far out as you can, helps those brakes last longer too.
