what?! in DS2 you can get very, very easily 4 guaranteed tittie slabs (i.e. no grinding) by the time you reach Drangleic castle (with a total guaranteed of at least 10). one is in the goddamned first real level of the game! chunks are aplenty, and if you don't have at least one +10 weapon by the time you finish Tseldora without a second of farming, you're doing something seriously wrong.
do you know how many guaranteed slabs you get in DS1 by midgame? 1. and there are only 3 guaranteed in the whole game.
Chunks are only aplenty if you beat the game, and they cost 6k each. You need 6 to level up a weapon. Slabs aren't a problem, chunks are.
Petrified Dragon Bones and Twinklings are a bitch to find and farm, and if you want to try a shiny boss weapon on higher new game cycles you pretty much need to get it to +5 so it deals decent damage.
In DS1 you need 10 demon titanite to level up a boss weapon, and its relatively easy to get; the respawnable titanite demon in lost izalith drops 2 at a time 100% of the time. 5 kills gives you a maxed out boss weapon.
In DS2 you need 15 dragon bones to level up a weapon. There is no enemy in the game that has a guaranteed drop rate, which means that you have to grind them for a very long time, and you'll probably only get one or two before despawning them. In order to keep farming you have to join a covenant (which makes them harder) or burn an aesthetic (which consumes a rare resource AND makes them harder).
You objectively have to grind more in DS2 in order to get a decent amount of boss weapon upgrade materials.
Not to mention that DS1 tells you your item discovery; DS2, for whatever reason, doesn't. Which means you have no idea how effective your farming gear is.
DS1 just handles farming better. You get more information and the drop rates aren't as low.
It is true that the Dark Souls games in general have a bit of farming for materials or weapons, but in DS2 it feels like a complete grind. I don't know how they handled it in DS3, but its certainly more tedious than DS1.