Lotro is my main MMO, and I play a lot of MMOs lol.
That being said, I am not at endgame in Lotro yet. I play Lotro for the story, and as such, I read every bit of quest dialogue in the game. I don't expect to hit endgame content in Lotro for a very, very long time, and I'm completely fine with that.
I look at Lotro as being different from games like WoW, EverQuest, and the sort. Lotro is a highly story-based MMORPG where experiencing the story along the way as you consume the content is a massive part of enjoying the game. I think of FFXIV in the same light. When it comes to the majority of MMORPGs like WoW and EverQuest, those games are all about leveling up and getting gear. The story is there, but it isn't the main focus of those games.
So, honestly, I think that whether Lotro is the right pick as YOUR main MMO is going to come down to what you want out of your experience playing the MMO.