I think EOS has 5% annual inflation. But EOS save 80% of inflation. What is purpose of this savings?
In the original white paper under Worker Proposal System you can find the description of a set of contracts which are funded by inflation and chosen by the community. As this system is not yet deployed, the funds that would go to them are being escrowed in a savings account so that they can be deployed to community chosen contracts at a later date IF the community elects to deploy such a system.