The boat comparison is still pretty nice here, think of manouvering your sailing boat within a port, it ♥♥♥♥♥♥♥ sucks and it slow. You do those things relatively rarely but honestly trying to pick up some item really close to a ledge is annoying as hell. "Platforming" like jumping and tight little movements however are actually legit clunky. Think of your character as a boat, but this kinda game is not a go-kart track but the open sea so the floaty controls fit well despite being floaty. You can argue that it's unresponsive and you aren't even wrong because your character obviously doesn't turn on the spot if you run into one direction and want to do a 180° turn, but it has a purpose and isn't just bad programming or something. The weight to your character and the movement is intended though, it's actually very fluid once you're in the flow. OP has a point, like the deadzone is there for a fact so there's definitely something wrong with the controls. Lots of people get really defensive in here, lol. The anti-cheat mechanics in this game as well as Dark Souls III are hot garbage.
There's a mod for that, "Souls Unsqueezed", but it may trigger a softban. Playing ultrawide might still be an issue. If you want a more faster paced and smooth Dark Souls, Dark Souls III is what you want.
Most japan-developed games don't support anything other than 16:9 (and maybe 4:3 but who still uses that). Only the remastered original Dark Souls, however seems to support ultrawide out of the box without mods.
There may be a way to mitigate the deadzone when messing with the controller options in Steam Big Picture mode. Turning down camera sensitivity made a lot better for me, might not for you. There is an analogue deadzone for some reason when using controller, which i can see how it may irritate some people. It's subjective, but i prefer the methodical approach to combat this enforces, unlike a more traditional hack 'n slash. How much control you'll have when swinging your weapon depends on the weapon used. I think this game's controls are noticeable less clunky than in the original Dark Souls.