Part of the problem here is the people are fooled into thinking that 90% of people who place bets are losers. That implies that 1 out of 10 people are winners, which many gamblers would be happy to take. In reality, for most non-skill based games you will find that 99.9% of people are losers, or a figure closer to that. As it comes down to simple math at the end of the day, take slot games for instance - people see a RTP figure of 95% and think that means they have a big chance of winning, but really it means you will on average lose 5% of your bet each time you gamble and ultimately it will drain away your balance until it reaches zero. Sport bets also have a comfortable buffer, or margin of error, built in for bookmakers who are equally very shrewd and constantly improving their prediction software to outplay you.
In bets, the chance is slightly higher, but it depends very much on the player. If a player uses risk management well, manages the bank well, does not break the rules of the betting and manages his emotions well, then he has a chance to be among those few players who will end up with a profit. But the vast majority will lose more than they win, this is what bookmakers make money on.