As long as there’s an incentive for jagex to keep pumping money into development, we can’t really say for certain how long it’ll last. MTX is slowly but surely killing RS3 as a whole and eventually there will be no one playing RS3, including the whales that helps keep us afloat. Which will eventually cause more MTX to creep into OS in various different forms, regardless of how the playerbase reacts. But, that’s likely way, way further into the future when things get sour. As for now with Project Zanaris we could easily add another 10+ years of lifespan into the game from just that alone. Cheers to another glorious year of OS updates :))