As someone else answered the main use case of PouchDB over plain browser storage is its ability to sync data. However just wanted to clarify that PouchDB doesn

As someone else answered the main use case of PouchDB over plain browser storage is its ability to sync data. However just wanted to clarify that PouchDB doesnt natively use localstorage for storage, its primarily IndexedDB or WebSQL in the browser (leveldb in node). We do actually use localstorage for cross tab messaging, but thats mostly a hack due to the lack of idb event listeners (that are coming in v2)