There's more to ED than just the surface stuff. It has a lot of game properties. What it doesn't have is a scripted progression with a finale. There's no end game. There are no heros or overlords.
What it does have is pretty substantial.
Economic progression - It's not like many others, but it's there. Gathering credits is just one part of it. Hoarding modules, modifying those modules with the currency of materials and data.
Tactical - Take those modules and ships and engage the enemy. Some are weak and others are strong. But there's no AI anywhere that can match a human on equal terms. Yet.
Role playing - You can be an explorer, a trader, pirate, bounty hunter or murderer. It takes some imagination to stay in the role and you'll likely need to use all of these roles to get where you eventually want to be.
Strategy - The ever-changing BGS is playable, but you need to search for the rules of the game. They change at least a little on every major update. A moving target, so your strategies need to adapt.
Simulation - You can fly your spaceship through the most accurate simulation of the Milky Way available in a game. As long as you accept the flying part to be more related to an aircraft than a spaceship.
Persistence - You never die unless you wipe your save. Even then, you're not really dead. You're just re-spawned at the starting line.
It has a lot to offer, but it can't be everything to everyone. Me? I like a lot of the game. Hate some of it and have learned to just accept some of it. Once in a while, you just have to walk away. But we always come back.