In most cases, yes, blackjack offers the best odds in a casino. This is largely because there are three outcomes here: a win, a loss, and a tie (push). Since the odds of a push rest at 8.48% and the chances of losing come in at 49.10%, the probability of winning a game of blackjack is high at 42.22%.
In reality, yes, plenty of people have earned their livelihood playing blackjack -- for the past 50-plus years. But it's not like they walk into the casino withR$1,000 and walk out withR$2,000 every day. Card counting provides a small edge over the house, typically 1%-2%.