I mean that's just an inherent issue of rating based on damage rather than direct measurement. Tornadoes are small and buildings/towns are also small (and the number of things that can yield an EF5 rating is even smaller). Even before 2013, only a fraction of the tornadoes that reached that intensity were rated as such.
I think this is the most impressive damage I've seen this season though, especially since I suspect the standard of construction is probably a bit higher than it was in Rolling Fork.