The overall Spool Protocol is built with two things in mind: Composability and Efficiency. Since we understand what a Spool Smart Vault is at this point, there are a few important additions that have to be made in order to fully grasp Spool.
The reason Spool is efficient is because every Smart Vault interacts with the same Strategy Adapters. Using the same Strategy Adapters means that when more Vaults are added to the ecosystem, rather than decreasing in efficiency, Spool actually increases in overall efficiency.
Anyone with a programming background will recognize that composability is the key to scalable infrastructure. This is why Spool works with an "adapter pattern" that unifies interfaces for Yield Generators. Constructing Spool like this allows easier future development and expansion of the ecosystem, as well as giving external protocols the ability to easily integrate with Spool.