I've noticed, that since the release of Shadowlands, everyone has been enticed to difficult content. But, as you continued releasing expansions, the game started to become easier (Excluding DB3, which is your way of covering up).
Shadowlands released, Penumbra, Inferno, Pandemonium added. The Beast added.
But, this was several years ago. And since then, every monster in each zone, has stayed the exact same. It's come down to, from needing a whole raid force to kill The Beast, to only needing four people, (Doc Crat Enf Sold or Engi). That's not how this game should be working.
Since the release of Lost Eden, as many people have said, the game has been very broken. Everyone has gotten extremely improved in the way of PvM, but the PvM content has stayed the same. So, what you have now, are people running around with 3,500 - 4,000 attack rating, 20,000+ HP, a couple thousand more AC's than previous years.
So, the point comes down to, while updating to new content, and adding things that buff more armor, health, and attack rating, buff the monsters in the game as well.
DB3 is a joke of an excuse to try and make the game harder, you don't insert content that is nearly impossible to do, and then say "here is your hard content, enjoy!"