Why do I need Roon?

I used to use amarra, pure music, and lastly audirvana. Roon surpasses them all for functionality and SQ. DS Lightning from Auralic and the LUMIN software would come in 2 and 3 behind Roon.
Roon provides such features that would, behard 

Roon provides features that would be hard for other vendors to implement for a free app. If you pay for an app specifically rather than a part of a product, you have the luxury of hiring more software developers that can tackle more features.