There's a lot that could have been done with Excavator. It looks cool and does damage, but it just doesn't really add much or fix/address feedback.
It's another way to generate Battery in AoE, while it just as easily could have been a cool way for us to expend Battery in AoE and give it a unique way of working with rotations and whatnot.
Have it spend 20 battery or smth so your burst phase could be *Gain max Battery, Activate Queen, use Chainsaw to get 20 Battery which is then spent on Excavator* or smth. Idrk i'm just spitballing ideas here

Point being that Excavator could have been a way to spend Battery or do something else to better address feedback, Instead it just appears as 'AoE Air anchor 2' or 'Chain Saw 2' without really adding much beyond that.

Expansions should address feedback and try to make the players excited or happy by doing the bigger job changes.