The house has an edge because you play your cards first, therefore you have to make a decision based on incomplete data.
Proper basic strategy dictates that the house edge varies based on the rules the house sets forth. This is dependent on # of decks, doubling and splitting rules, hit/stand soft 17, surrender, and any other variables.
There was a time when a few casinos offered games that gave the players the edge off of the top of the deck due to player-beneficial rules.
The house edge after each hand is dependent on the composition of the remaining cards left in the deck. I won't go into the math, but the house edge changes every hand.
There are ways to nullify rules that give the house the edge, but that is another topic beyond the scope of this discussion.