The concept of endgame doesn't necessarily mean that the game is over. It can also mean that one already reached the maximum possible level. Or in other words, that there is no other level above that. For some, the fun is to get the best of anything in the game, for others, the fun might be in something else.
In my case, one of the things that keep me going - but not the only one - is wondering what is it like to fly other ships. I have no hurry in doing so, but I am sure that once I tried them all, and once I get a Corvette or an Anaconda, the motivation to keep playing will potentially go down (unless the game seriously improve towards more player interaction and cooperative play). I guess this holds true to many, if not most players around.
Nevertheless, if we define 'endgame' in a more strict way, as some sort of 'game over', then yes. Elite doesn't have that. But is similar to WoW and others; once you get the max of everything, you can still play, on and on.
Whether or not you feel like playing the game or not after reaching such point has nothing to do with being better at it or not understanding the game though.