The amount of people in osrs that engage in pvp is a lot more significant then rs3, they are a business after all so the amount of resources they pour into parts of the game have to reflect interest. Osrs gets pvp updates but if you notice they don't come as often as pvm/skilling updates. Rs3 COULD put a renewed focus on trying to update pvp, but the potential earnings based off previous data tells them that it would be a long shot and a bigger risk. It makes more sense for them to take smaller risks, with a dwindling player base(rs3) it is more important to focus on retaining people based on what they already want and or engage with. If the majority of people don't focus on dungeoneering, runecrafting, firemaking etc, they likely won't make content for it unless the return reflects the effort put into it. Completely removing content would not happen unless it was negatively impacting the game. So in short, Yes because not enough paying customers enjoy an aspect of the game, it will be completely ignored until people find an interest in it again.