For example, some slot machines are programmed for low winnings and it's not about the RTP. It's just that the mathematical model of individual slots was initially built very poorly.
🏆 For example, my favorite slots are from the following software - Push Gaming, Relax Gaming, Netent.
So you're don't trust with the RTP rate, but you choose those three providers are your favorite slots? that's not make sense, it's just your belief and there's no proof if the three providers above are better than the others. You're just lucky when you played those slots and unlucky on the others.
The providers can know the RTP rates of each slot by wagering more than 1 Million bets, so it's really high.