Is an actual c++ implementation of the java's nio is strictly better than nginx's one? Is it using epool() and sendfine()? Isn't all those java's abstraction le

Is an actual c++ implementation of the java's nio is strictly better than nginx's one? Is it using epool() and sendfine()? Isn't all those java's abstraction leyers are overhead? It seems like yet another attempt to put some more air into java's bubble.