There are loads of card counters around. I dont know of many who are successful in a modern casino with shuffle machines. Most of the successful players at card games I've found involve collusion with the dealer.
Even with no shuffle machine, though I'm not sure where else still plays with a good penetration, everywhere in Canada, we seem to give 50% penetration for a double deck. We even had a 6 deck shoe once which was approx 75% penetration but they decided to remove the game overall as it wasn't beneficial to the casino.
Rebirth, what game do you play then? I agree about card counting. The conditions needed are to rare. There are exceptions but it's not like it used to be. You might want to look into shuffle analysis. It can make a significant difference. It can be combined with counting.
Its not hard to have a reasonable idea of a possible counter or ap working card games. But being sure of it takes a lot of play analysis. Still though if we suspected a player we checked them in the database and added them. Knowing someone doing shuffle analysis not really possible