In my opinion, card counting is applicable to online and physical casinos. I think iit works better in online casinos because there is nothing the house can do. There are other solutions and the solutions above are applicable mostly in physical casinos.
You are very much wrong I have not seen one blackjack players here that take down a blackjack site because he ius using a card counting method to beat the house, because they have a counter to this which is the continuous shuffle machines.
These perpetual shufflers make it almost impossible for card counters