Seriously, would you bother with high ground if the only effect were +2 AC?
I'm in the group that feel height should only apply extra range to physical attacks(arrows/bolts), though honestly I'd be perfectly fine with no mechanical advantages automatically applied for occupying higher ground. It has inherent advantages already.
High ground generally means a ladder or stairway type limited access...that is a choke point that can be used to block melee attackers and keep them off your ranged.
High ground allows the use of the much argued bonus action Shove ability.
A ranged toon on high ground can back up a few steps and break LoS for ranged toons trying to hit them from below. You don't need cover rules if you start your turn outta sight, step forward and cast/shoot, step back outta sight again.
Removing advantage/disadvantage from height would in no way make higher ground useless, it just wouldn't be "I Win".
