The first Dark Souls is a masterpiece. No other way to look at it. Sure it had it's problems, and of course it was the worst PC port in the history of gaming, However the atmosphere, the level Design, the WORLD design, paired with the greatest melee combat system in an ARPG to date(surpassed only by the following titles in the series) made it a legendary game that changed gaming forever. And it definetely had a story. It was just that the story/lore was hidden in obsure NPC clues and item description. This new way of story telling was also very interesting at that point.
I feel the same way about The Witcher 2. In my opinion it is a legendary game. It had the greatest visuals/graphics than ANY RPG to date, amazing atmosphere, and a choice and consequence system that was so important that effectively completely changed over 1/3 of the entire game based on your choices, something that to my knowledge had not happened before. Pair that to one of the greatest main quests ever, a very complex political thriller with entirely grey choices, with nothing even remotely semembling a clear good or bad decisions, and you have the materpiece. ALso the combat, despite getting a ton of shit, it was definetely one of the greatest in any WESTERN Action RPG to date, and it was quite hardcore. For me The Witcher 2, in terms of world, quests, dialogues had zero weak spots. The Witcher 3 is one of the greatest games ever created in any genre, but to me personally it will always be inferior to The Witcher 2, because it definetely has weak spots, even in the main quest(some might argue ESPECIALLY in the main quest), and i do not like very much some of it's more mainstream influences.
However, getting back to the original question, even though i think that Dark Souls 2 and Dark Souls 3 are also amazing games, they feel like the same game as the first one, with just improved aspects of the gameplay, and far worse Level/World design and atmosphere, while one cannot praise enough the amount of work that CDPR has put in their sequels. You can see how hard they worked and how many things they changed in their attempt to improve their games from one another(despite if some people including me might prefer an older entry), instead of playing it safe and building entirely upon the previous. In that regard The Witcher 3 to me is vastly superior to Dark Sous 3. The amount of work that has been put on it is not something to be taken lightly.
I conclusion, since you are comparing 2 of my favourite games(series actually) of all time, to me the original Dark Souls, the Witcher 2 and the Wtcher 3 are the best RPGs since Baldur's gate 2.