ETOPS vs. Non-ETOPS Route Question?

It's my understanding that in order to make long distance flight more economical, ETOPS was developed to allow twin engine planes to fly very long distances, but they still have to maintain a safe distance from any airport that they must make a single engine landing at from what is considered safe by industry standards and practical in terms of flight times. This is true no matter if they fly over water or land, so it stands to reason that they do not follow the same routes as say a four engine plane would. But I'm not a commercial pilot either.