They're on the
roof of the building. How is this any "thicker" than Dressrosa? Are you mentally ok?
The attack never landed on Dressrosa. It overtook Doflamingo's strongest attack, overtook Spider's Web, KOed, and then used his BODY to split the ground.
Seriously, use your brain.
KKG is certainly stronger than that ^. That's an island splitter.