The biggest advantage I see in power armor is actually the ability to have an on board computer system & act as the command and control element for a unit of drones. If each PA wearer is in command of a number of robots using optical links for comms (to prevent EM jammers being an issue), that'd be a great way of retaining local human control while gaining all those nice Terminator advantages. One of the big issues with drones is jammers & latency - having each PA troop acting as a local "Node" in a decentralized automated warfare unit would help to offset that.
That and NBC protection, less damage from small arms & random shrapnel, and the ability to more easily cart around shoulder fired SAM systems - or a Davy Crocket haha.