The reason the lore rewards for older lvl 60 dungeons was lowered is because those dungeons aren't ilvl synced making them almost trivially easy and very quick to run. ARF is ilvl synced and offers no gear which is why its lore reward is so substancial.

I don't disagree that ARF is getting boring. I have run it a lot just doing the roulette. Frankly I think the Anima weapon is a little too reliant on lore for progress. It effectively limits your options on what content you can use if you want to grind your relic. However I don't think you would see them just buff all the other dungeons. They lowered those lore quantities for a reason. Realistically I think it would be more likely that they lower ARF's lore rewards than buff the others.

I do think the fact your suffering downtime is strange. I haven't had this problem at all and I do almost every dungeon run at 60 as a WHM. What is your Peity like?