RTP is a long-run guide, not a sure win. At 96% RTP, the house edge is 4%:...

https://emilianosexcellentcolumn.scriblorax.com/posts/if-house-edge-is-fixed-what-can-i-control-as-a-player

RTP is a long-run guide, not a sure win. At 96% RTP, the house edge is 4%: about £4 per £100 bet, on average. Volatility is how wins land: high can mean big, rare wins; low, smaller wins more often