In a slot there is always the possibility of winning on any shot, I have rarely played slots, but I have made the mistake of betting a lot of money and I lose quickly, thinking that in the first attempts I will have free shots or have a good reward
But it turns out that the greatest probability of winning is to play for a long time, that is, as in the traditional slots of physical casinos where there are people who last hours playing, here you may not last hours, but you don't have to play so fast, thinking that the high RTP is going to help me, you have to take into account the random factor and the luck factor sometimes, I think that the platforms put a high RTP to attract people, the pragmatic games attract my attention, because at the least expected moment they can give you a great reward, maybe that's why I made big bets thinking that you were going to win fast.
We well know that in most RTP games the figure will be expressed as a percentage of the house edge, an example would be European roulette
which has a declared house edge of 2.7%. That figure means that for every $100 a player wagers, they are expected to lose $2.7.
Although it may not seem like much, there is always the possibility that you can come out of a single session as a winner.
Source on the example of European roulette:
https://edge.twinspires.com/casino-news/what-is-return-to-player-rtp-in-casinos/