There are plenty of ways to build a cabinet.
If you use battens, I would say that dadoes and rabbets are unnecessary. If you're not using battens, then dadoes and rabbets are beneficial.
My experience has shown me that dadoes and rabbets can help with glue up and keeping pieces from wandering away too much. It also will ensure a stronger overall structure, which can never hurt, especially when it doesn't come with any weight gain.
Tools on hand will probably be the biggest factor here, but if you have a router or table saw, then cutting grooves ain't that hard IMO.