Gracie Jiu-Jitsu in MMA on the decline?

Has the gracie jiu-jitsu in MMA improved or declined? With the current crop of fighters in the modern era such as Roger and kron,rorion,rener are they a improvement in mma bjj over the older generation such rickson and Royce royler?

People are just better at defending now. Not a decline just the way it is actually Phone Post 3.0