RTP is a long-run average; the house edge is the casino’s mathematical share:...
https://www.quantifiedstrategies.com/rtp-variance-and-expected-value-applying-a-quantitative-framework-to-online-casino-gaming/
RTP is a long-run average; the house edge is the casino’s mathematical share: 96% RTP = 4% house edge. Volatility shapes how wins and losses cluster