Bugs eat quills, but not beads. Quills grow brittle, can be abraded away, and if done with sinew or cotton thread, well, all natural materials break down.
I occasionally do lane stitch work using beads and Nymo thread, and it is very durable.
I live in awe of quillworkers. Their work is of an earlier time, and is more closely related to the environment than man-made glass beads. The work is also much lighter to carry, definitely a factor to me, and my heel spur.
I had the good fortune to view Ms. Parker's excellent work at ATAR one year, and I would beat a path to her were I looking to have my quiver embellished.
Killdeer