The actual materials used don't necessarily make the bow. I'm sure there are other materials that will work in this situation. The person that came up with this idea did lots of research as to the proper materials for the end result desired. If you are willing to experiment with different options and are willing to fail, possibly multiple times, with success as your ultimate goal, I'm sure you will come up alternative materials for the same final results.
Don't stop thinking! We wouldn't where we are today in natural archery if folks just quit thinking and followed the pack. If one idea doesn't work, try another and another until you find one that does work.