Card counting is romanticized but really it is almost impossible to get away with now (while making any meaningful money). The whole premise of card counting is to vary your bets where you are betting more when the count is in your favor, and less when it isn't. Also "penetration" into the deck is important because the less cards there are remaining in the deck the probability of you getting the cards you want (positive count big cards) is higher.

So with that said:

- Casinos employ methods such as continuous shuffling machines that make counting impossible. Tables that have hand shuffling of 6-8 decks cut the deck and reshuffle with 2 decks remaining or so. So it is harder to get penetration.

- The way to be maximally profitable is to vary your bet very widely depending on how positive the deck is. This could be 30x your low bet. Behavior like this will get you detected.

- Security personnel and even dealers keep counts. It is not some savant activity. It is not hard especially since all these people do all day is look at cards. So they know when the deck is positive and if you are always betting big when that happens you will be detected.

So the people that are left counting have to avoid heat by "camouflaging" their actions. They don't vary their bet that widely and make purposeful bad decisions to make it appear they are not keeping a count. They want to appear like someone that does not know how to play basic strategy and raises and lowers their bets based on superstition (there's a lot of them). This all eats into their advantage substantially. Then in addition betting big at high limit tables is going to be more carefully scrutinized as well.

With that all added together the life for a modern card counter is grinding out for comps and very low player advantage for very long times. Casinos aren't dumb anymore. So while we watch the chronicles of the MIT team, and others, those days are long, long gone. Makes for great stories as people love Robin Hood like tales, but it just isn't happening like this anymore.

Edit: Also the tactic she mentions: Entering a game mid shoe after watching for a while, and waiting for a positive deck, is called "Wonging" After Stanford Wong a longtime gambling expert and advantage player. There is NO WAY you'd get away with "flashy big bettor Carlos" coming in after she counted detected a positive count. Tables with any meaningful limit usually do not allow mid shoe entry for this reason. It is one of the oldest tricks in the book and you wouldn't get away with that for long or at all.