I've been an engineer main since launch and took a break recently and am now coming back, so while I don't know if we're in a super awful spot performance wise, there are a lot of things that seem ridiculous to exist.
As you said, turrets (other than heal turret, and rifle turret just for static discharge builds) have been useless for all of the game except for that one time it was stupidly overpowered in PvP before the first expansion (remember that?)
Our absolute dependence on grenade kit since launch has been insane. There has been no attempt to change that.
Elixir X is still just a random chance between a Warrior (or Necromancer if underwater) and Elementalist core elite skill. No Engineer identity.
The reveal of the shortbow on livestream followed by its boring and lacklustre reviews by other players shows that they really haven't changed in regards to how they make things for the engineer.
I'm tempted to just change my main from engineer to warrior. With the new changes, power berserker seems fun.