To say you are skilled in PvE is like saying you are good at putting a fork in your hand.
No matter what Anet does the content is going to be easy. It comes down to the combat mechanics and the AI. PvE mobs just don’t have enough variety in the skills that they can use.
Most PvE mobs only do 3 things now as far as mobility. They either bee line towards you, stay where you aggroed them and range you, or run away at low health. They all need better movement such as dodging.
There are too few skills and not enough randomness. The mobs will actually wait for you to use a certain skill before they use whatever skill that CCs. Though this is good for interrupting the player it is just too predictable.
So what PvE mobs need is more skills , movement, and randomness.