Bag interiors can have a range of “shagginess” on the interior - this is a normal feature of leather hides and nothing to be alarmed by! Our leather comes from cows and each animal's skin is a different thickness, which affects the tightness or looseness of the grain. Some cows quite literally have thicker skin than others. Because we prefer our leather to be thick (roughly 2 mm!) we aren't always able to shave off the entirety of the loose fibers of skin that are closer to the muscle on smaller cows. This means that we often receive a percentage of hides where the fibers on the suede are sort of shaggy and may be more prone to shedding.
If you are experiencing fibers shedding you can either use a standard lint roller to help remove loose fibers and prevent future leather bits from coating your belongings, or a vacuum cleaner works, too!