For the most parts I agree with you. Betting sites need to make money, not make their clients rich, that's their business. Usually if you will add opposite bets, total probability by odds will be 90%, not 100%, that's how they make money. Every smart person knows there are no such thing as risk free bets. Even fixed games aren't risk free, they can fail (and I'm totally against fixed games). You don't bet on things with too low odds at all and your unit size for most risky bets should not exceed 2% of your total bankroll. There are similarities in risk management with sports betting and financial markets. If you understand that and are disciplined it's hard to get rekt (basically, you can get rekt only if you bet more than you can afford to lose).