They mean skillers in general sense, the ones who focus on skilling game play. Players who spend 90% of their time doing non-combat skilling but still engage in pvm activities such as BA, and pvp activities such as Warbands, for skilling resources and xp gain are still skillers.
Note that pvmers have to level plenty of non-combat skills like Herblore, Invention, Archaeology etc to harness the best pvm benefits, why will skillers have a problem just spending a tiny fraction of time killing a few mobs, especially when they have the choices of killing Lumbridge rats.
They have actually talking about "skill pures" in today's livestream. They said these tiny number of the RS3 community choose not to level up combat, but the game is not designed just for them. Note that skill pures have problems long ago they can't complete most quests, even the RSC ones, why is there a problem now in 2023 with Necromancy?
31-May-2023 19:32:31