The reason for that level of sucess is because it does better what it proposes to do, which is to be a good store of value and censorship resistant. Most other currencies try to do the same, but there is no way for them to achieve this being so centralized.
Thats true, I think the most unique feature that Bitcoin contain is its Volatily feature that it possessed , and I think it help workers like you and me to make our profits be substantial to increase and used for our different purposes.