The work of the Avatara is not to create a new sect, religion or philosophy but to open the way for the future. For this He has to go down into the obstructing coils of darkness that prevent the world’s onward march.
This then is the real reason for suffering here, - Ignorance that prevents us from becoming aware of our own Truth. But Ignorance itself has its support and base in the Inconscient that would not easily allow the change.