I just started leveling ARC/BRD and, in my opinion, if they're going to add item level requirements to leveling dungeons/trials (assuming they figure out what to do with roulettes), they should focus on the left side (including weapon slot). There just seems to be a lack of accessories at certain levels unless you go the crafted route or you get lucky with dungeon drops. That said, the situation is much better with Stormblood (and maybe Heavensward?) dungeons, since you get guaranteed drops, including accessories. So maybe just for ARR at least.