She is not. Rihanna has outdone and is still outdoing what Beyonce was doing at the same age, and it's not like Rihanna hasn't slipped and jumped back up many times before.
So let's wait until Rihanna turns 34 and then compare. This is like comparing the salary of a freshman working at McDonalds to that of his father.
She's known for having some of the best tours in music, and always putting on a great show. The Last Girl on Earth tour stopped Rih from becoming a massive touring phenomenon. But with the ANTI tour's rave reviews, she still has plenty of time to build back her tour base.