To answer this question the reason is because eve’s engine was designed in a way where the development team has to manually create the solar systems, quests, stations and all the functionality there in. They are literally hand-sculpting them.
ED is on a newer engine that has capabilities that eve currently does not.
We should also back up and mention that eve in terms of mmo standings is far superior to ed due to the very reason this topic is being posted (extensive amounts of space).
On that very note of large amounts of space there is no interaction of players because eves combat takes place around an object (station, gate, planet, moon, ss etc) where eds engagements can literally take place anywhere in open space, which is not at all a good way to facilitate content. For this reason eve is far more accurate to be called an mmo and ED an online singular player game that calls itself an mmo.
Yes, ed has some things in it that are better, but as it stands for an online game its really subpar and will always be the case because of this very reason (to much space)