The base game wasn't designed with mounts in mind and has teleport waypoints all over the place. The only place that "requires" mounts is the expansion you get them in and they are disabled in many areas in the base game/instances whatnot. Gliding is also an expansion feature and isn't necessary in the base game.
The end in GW2 is when ever you get tired of the story. The gear you got 10 years ago is still relevant today which is nice if you wanna drop the game for years at a time. And the living world stuff isn't required for content so if you didn't log in to unlock it at the time you don't have to worry about buying it if you don't want to.