I think card counting remains effective in modern casinos but is increasingly difficult due to countermeasures. Casinos use multiple decks, automatic shufflers, and frequent reshuffling to disrupt counting strategies and I believe surveillance and pit bosses monitor for card counters, leading to potential bans. Despite these challenges, skilled players who remain discreet and adaptable can still use card counting to gain an edge in favorable conditions, particularly in games with fewer decks and predictable dealer behavior.