Not true in Nigeria…if you use an ATM from the same bank you hold your account, you won’t be charged any fee. If you use another bank’s ATM, you’ll be charged a flat fee of 35 naira ($0.08).
Wouldn’t the 5% be on top of an ATM? Plus a regular cash user (not a trapped tourist) is going to be using a free one or withdrawing for free from a teller.
I'm in SEA, Cambodia to be specific, and the ATM % fee is around 1%. This is quite an improvement from a few years ago (where 5% was expected).