I play a few hours a week, there is still so much more content in the game for me to play that I have stuff to do for years.
The only thing I ever had to grind was my Heart of Wood doing challenges. and that only took a few hours.
I solo everything exclusively save VoD, the only raid I ever did...once, I am in a Large guild on Sarlona that is solo'er friendly (they never force me to do anything, they ask if I want to participate, but don't get offended if I don't). I only ever did 1 raid with my guild, and I was basically a spectator because I was clueless, it was more of a learning run for me and to take screen caps.
Like everything in life you should do things in moderation, too much of a good thing...is... well...isn't good !! You exhausted the content by speeding through it or grinding the Cr*p out of it...and you wonder why you're burnt out?