Huh, I went through all the chalice dungeons offline, and I had no problem with finding all the materials I needed by going through them once. I even ended up having some extra materials to open some root chalices.
There should be a challenge involved in getting the best gems. Getting them from the main game would be no challenge at all. That being said, you can get +22.3% physical attack gems from the Winter Lanterns before OoK.
But they only drop physical gems. They don't drop fire attack up gems, arcane attack up gems, bloodtinge gems, fools gems, nourishing gems, etc. They don't even drop thrust attack up or blunt attack up gems, just phy attack up and they aren't even the best phy attack up gems, just merely decent for when you can get them. I mean, there's really no reason why those two winter lanterns in the dlc don't drop 27% attack up gems. I mean, unless you mlg pro, your going to be doing that at the end of the game with +10 weapons so why don't they have a chance to drop some of the best gems for phyical in the game? Makes no sense. Hell you can even make the chance for 27% gems really rare. Like 1% chance with no item find but there's no reason they shouldn't be able to drop them.
Personally, I find the chalice dungeons quite boring and tedious so I don't want to be in there any longer than I have to and I'm sure many players feel the same so to say to someone, "Hey, instead of farming for the thing you want. Your going to have to farm for the mats to open to up the dungeon to have a "chance" to get the thing you want" is shit imo. There's a good chance you might get bad rng and not get the gems you want and have to do the dungeon all over again or have to go farm more mats so that you can have open up the dungeon to have the chance of getting it again if you don't have internet or ps+. Its just really poorly thoughtout imo. Just make it more straightforward and don't make us farm so much for mats and don't tie rng to it and it would be significantly better.