A fair point for sure
Something that I've pointed out enough times before but I think is worth repeating, is that the game has so many different aspects to it
- Levelling
- PvP
- Bossing
- Quests
- Exploring
- Building kit
- Growing pets
- Leadership (organised hunts)
- Socialising
- Helping newbies
Some people pick one of the above aspects and only do that one thing, and that's a completely valid way to play if that's the one thing you enjoy.
But I do notice that any time anyone complains about boredom, it's always people who are focused on one or two of those things.
People who do all (or most) of those activities find a lot more enjoyment in the game and are generally happier.
My advice to someone who is bored is to pick something from that list that you normally don't do, and give it a try. Blindly adding new caves only kicks the can down the road a few months and you'll be bored again, it doesn't solve any actual problem.