All of the Souls games are basically this: if you're not afraid to die, and you don't get frustrated trying and re-trying things, it's not "hard". It's just a learning experience. I am fine for a while, and then somewhere along the way I get tired of fighting <insert boss name here> for the 10th time, giving up and meaning to come back to it...and then I never do.
For the record, though, I think Dark Souls 3 is the best souls game to date. It's like a mix between Bloodborne's pace and the "older" Souls' pace. Combat is faster, but not as fast as BB.
And I have no idea if the "Ashen Estus Flask" ever existed in the game, but that is a GAME CHANGER. Being able to refill your mana in between bonfire rests is massive. And giving you the option at the smith to set your ratio? (I want 1 estus flask and 3 ashen estus flask, or 2 and 2, etc.) is a stroke of genius. I've never used Magic in a souls game, but because of that Ashen Estus flask I ended up rolling a deprived and he's not a jack of all trades character that can handle most situations adequately, but none of them exceptionally
And they seem to have learned from BB in other ways--they throw more enemies at you per encounter in this one, but they're easier to kill. Usually a one hit with a good melee character, but they might have a shielded or heavily armored enemy mixed in, or a caster up high (or archer shooting sh*t at you).
Honestly, I think it's like they took everything they've learned over the years and made the super-game. It's incredible.