Why is there an option to rebuild/reorganize an index when SQL Server does this automatically? SQL Server automatically handles index fragmentation issue when a certain number of rows are inserted/updated.
Then why is there an option to rebuild/reorganize an index?
Are you confusing fragmentation with statistics?
There is no auto handling of fragmentation. Do you have some reference to point to?
There is, however, auto update of statistics. It is a bit crude, which is why we might complement it with scheduled stats update jobs.