I played GW2 for 300 hours at launch, then I kinda got sick of it.
Back then the lvl 80 areas were completely bugged and undercooked and what I liked about the early game didn't apply to them but they were the best place for the pink currency grind for the high level armor so I kinda had to spend the time there.
WvWvW started well and fun, then it became just a zergfest that we won most of the time. The instanced dungeons were a bit of a mess because like Tragic says, without a clear role it was hard to get everyone on the same page and I think that also made them mechanically less interesting to do, and then the one I wanted to do for a specific set of armor was one the guild didn't want to do often if ever anyways, so PUGing that shit was the worst.
The good things about the game for me were: climbing puzzles, that you could visit and complete every area regardless of level and still get story and rewards, and the big public dragon bosses. But there is only so much of that stuff you can do before getting bored.
I logged in yesterday and they've changed a lot of stuff that I think the best thing would be to start over with a fresh character because I felt completely lost. The clock tower was still a pain to do and apparently my witch costume can't use her broom anymore for some reason.
The one thing I really regret was selling my Mystic Conduit. I sold it to get some gems for bank space back then but now it is going for like 400 gold and I only have 30 on me. Lame.