When it comes to Blackjack and Blackjack strategy there are two camps. Those who use blackjack card counting and those who don’t. Card counting tends to be the domain of the more experienced blackjack players.
The casual blackjack player who is only going to play a number of hands doesn’t need to go to the extent of card counting. Maybe they have just started playing online blackjack and don't yet know what they really want.
But for a blackjack player who is going to spend hour after hour and night after night at the blackjack table, every thing makes a difference and card counting definitely does that.
Over the long run, card counting can represent a gain hundreds of thousands of dollars to the serious blackjack players. This is the exact reason why casinos want to try and prevent it.
A professional blackjack player will know what to do with a 12 against the dealers 9 but the social player will have no idea and just play with their instincts. The same thing when it comes to other aspects of Blackjack such as splitting and doubling.
If a person becomes more serious about their blackjack, well then maybe counting cards is the way to go, but they have to be prepared to be committed and dedicated to their blackjack.