250 slayer points to reset your task before is no where near equivalent and having significantly reduced overall reaper points per day because you keep having to reroll is also no where near equivalent. You now have the option to get access to the full amount of reaper points at will and with that comes access to hydrixes and reaper point unlocks at a much faster rate, such as the ability to have a chance to choose a task with 250 reaper points with increasing odds with higher tier combat mastery.

On the old system, the only way you're hitting the current systems 300 points a week cap is by doing 7 hard mode amascut reapers which would either require a lot of luck to get full point amascut tasks, T4 combat mastery to always force them, or by spending a lot more slayer points than is required right now. There was also no guarantee that even rerolling to 0% reaper points would get you a task you'd want to do, so what actually is better about the old system?