There's two significant issues in my mind when it comes to your prestige system idea:
1. Most quests aren't designed to be repeatable, making the process of getting them to be repeatable fairly resource intensive (this was brought up when pure resets came out and had to undo certain quests). This combined with the generally low amount people replay the quests that are currently replayable (Broken Home and Dimension of Disaster) has Jagex hesitant to make more quests replayable given the apparent low returns.
2. Questlines in Runescape take a long time to end and can go on to play into other questlines (ex: Ritual of the Mahjarrat's requirements). So in order to implement your suggested prestige system, they either have to adjust it every time a new installment to a series came out (resource intensive) or create cut-off points where events in quests afterwards simply cannot be affected by decisions made prior to that point (which cheapens the decisions we make by limiting their impact).
So I still find the best solution to be to let players replay quests that are significantly influenced by past decisions and let them pick and choose from the possible results of past decisions for said replay (as they said they are doing for Sliske's Endgame). Their first play through would remain their canon choice, however.
03-Oct-2017 16:23:20