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.
Isn't it true? We always hear that house has the advantage and then there is a house edge in which a bettor will just lose in the long term of playing a gambling. Only a tiny percent of people can get lucky some times but it's okay because gambling is not about earning a profit anyway but it's about having fun and passing the time.
We should only use small amounts for it so that we won't mind our losses and we won't get addicted in the game. What you said about slot is true and I was one of those people who believe on it but even so, I was still prone to losses. Never tried sports betting yet but its winning rate must be higher than slot and other luck-based games.