Originally Posted by
Huehuecoyotl
Not only is everything in GW2 accessible, most of it you can do in the way you want to. As an example, one of the first extra zones in the original game was a place called Dry Top. That has a whole bunch of insect in amber weapon skins that you can collect. You can still go back to that zone today and find people running it to allow you to get those skins. Or you can go into WvW (which is kind of large scale PvP) and collect all the skins as you play it.
You can do the same thing with skins and sets from dungeons, if you want. Or do it in organised PvP if you want. The best thing about it is that you play at your pace, in the content that you want to do. There really isn't any steering, which after WoW will either feel like a great relief or just strange.