RTP is a long-run average, while house edge is the casino’s expected share: 96%...
https://www.quantifiedstrategies.com/rtp-variance-and-expected-value-applying-a-quantitative-framework-to-online-casino-gaming/
RTP is a long-run average, while house edge is the casino’s expected share: 96% RTP = 4% house edge. Volatility shapes how wins and losses are distributed. In a short session, results can vary widely, so the average is no promise of what you’ll get.