Civ 5 and 6 introduced unit stacking constraints that completely change the way the game is played.
If WW2 happened in Civ 5 or 6, the Normandy landings would not have been possible because you would not be able to stack large number of units in one tile. Those landings were "a death stack".
But even if every large battle in history could be represented as a "death stack", Civ 5 and 6 players do not like them.
Then, the hex tiles do not create a good keyboard experience.