2.XX end game Coil / Savage, EX, Hard Dungeons, CT, varies other content that was added with at level cap. 3.XX end game content is elite dungeons, EX Trials, Alex / Savage, Void Ark, and whatever SE adds that requires level 60. So no, End Game isn't just Alex, just a limit people placed on themselves.
As for Alex loot system, it is a response to the community who complained about random gear drops from Crystal Tower where players had to run it many many times to get the right drop. I believe it's a little better than CT because I have more Alex gear in three weeks than I would have in Crystal Tower. But if you have a better way to remove gating but keep players actively playing without burning through content feel free to post it because I don't. I know without gating progression, people would spam everything in a week then stop playing and start complaining about lack of content. If you make it so mind numbing slow other players would be so overwhelmed they would just stop because they just can't catch up.
SE isn't perfect but almost found a good balance between content patch update and the amount of time it takes to finish personal goals of current content. You can almost set your watch to the "I'm bored" complaint threads on the forums and the release of a new update.