A cool addition in order to get rid of all those annoying .yml userdata (with 300+ yml opening that folder gets harder and harder), would be adding the possibility to use MySQL or SQLite databases.
SQLite would be cool for those server owners that don't know / can't configure a MySQL server but they want a compact database.
MySQL would be cool for server owners that want all data organized in their sql databases (also for web-hooks).

Another addition that would be very useful is a userdata timer that deletes all user data older than x days, configurable in the config.yml, this way if you still want to keep .yml database at least you just have to deal with the active users' userdata.

Database support has been suggested many times, and deemed unfeasible by the original Essentials author and rejected by the current maintainer.

See #167, #241 and #440.

Ok sorry