I've often wondered how the sandbox style of OSRS would fare with RuneScape Gold different mechanics, but they would probably take away from the 3-dimensional advancement in OSRS. A lot of popular MMOs such as FF14 make use of the progression system as an opportunity to help you learn the combat mechanics. The benefit of OSRS is that "simple" fighting mechanics enable the game to be explored in any direction.

RS3 gives us hints and I believe it may be worth a try if some of the guardrails are avoided. RS3 was trapped in an unsteady slope carrot-stick for a long time before Invention and Archaeology helped create an alternative demand economy and helped solve a number of problems. But we do see that, as a result of the design of RS3, the progression of abilities must be faster in order for to make the system of combat and unlock scheme to be logical. It's mostly progressed by bonus XP and dailyscape weekends that cause bottlenecks and can be very harmful to sandbox gameplay. Nevertheless, the ironman mode is amazing in RS3 and shows how the Runescape model is capable of standing up to a modern mechanic system.

I actually like OSRS IM mode a lot better.

POH can be found sucking balls in RS3 while in OSRS I can reach virtually any location in Gielinor with my POH. Farming cape sucks balls RS3 (small chance for an immediate harvest and notes the harvest) while in OSRS it gets me to a bank, a spirit tree, and my POH.

99 crafting is easy thanks to seaweed farming in OSRS which is not available in RS3. Seeds are easy to obtain using rogues in OSRS It isn't present in RS3 (it is , but it's not the doubling effect) AFK prayer training by cutting Sulliusceps in OSRS is not available in RS3. Making money from OSRS is also an easy task thanks to blood runes (~330k/hr), not present in RS3.

I had a 2k+ iron in OSRS at the time I decided to test RS3 IM for test and I was actually extremely surprised OSRS is much more user-friendly on IM then RS3. RS3 is usually referred to as easyscape due its massive rates of XP. However, in terms of IM, OSRS is A lot more optimized for game than RS3 is.

RS3 is only an easyscape option if you make use of dailies as well as XP events. The developers have also employed these concepts to make it harder to fix bad gameplay loops. The example of farming is great, they just don't give any thought to giving players seeds as the XP is possible to abuse with daily PoF. Idk if it's worse or better, daily scape is probably best for 1-2 hour per day informal, but cheap osrs accounts it's a nightmare for those who prefer immersion.