I personally platinumed Nioh and I certainly agree with some of your earlier points in the thread that some aspects of the game were shallow. Two of the main problems I had with the original game was:Nioh & Nioh 2 - As promised I went back and beat the human boss I left off at in Nioh 1, and I could see why I left because he's a real bitch that can literally kill you as soon as you enter the room. I almost had him traditionally, got his final phase to a sliver of life, but by this point he's constantly throwing fire, lighting and energy balls around and I just ran out of healing and rng. So I switched things up and tried every trick but I eventually just floored him with repeated Guardian attacks so he couldn't even go into his second phase. I think the 2nd phase prompt actually helped because instead of attacking again he'd hesitate before starting that animation, leaving you free to knock him down again instead; of course, I didn't know that the first few times I tried this so was too cautious, allowing him to make the change several times.
So, that was really annoying, and then back in Nioh 2 it turned out I was at another annoying boss, Shibata Katsuie, who had basically become a giant Yokai boar, but was also super fast, aggressive and like the previous fight was hitting me as soon as I entered the boss room. Fortunately, he didn't hit as hard despite his appearance, and was susceptible to poisoning, so he wasn't so bad once I hit him with that along with sloth and blindness to keep him off me.
Since then I beat the final boss of Nioh's last DLC, which was relatively easy because you automatically have an unkillable helper character, so you can just stay away for the most part and let them do the work. In Nioh 2 I've progressed a couple more stages and took down a few more bosses including a literal giant, which was pretty fun. After my first earnest attempt, which took like 15 minutes because it's a gimmick fight where you have to break up certain parts of his body to do a pre-set amount of damage when he staggers, I think I spent more experimenting with different weapons and abilities and exiting than actually fighting him. Finally, I settled on a super tanky build so I didn't have to worry about random insta-kills and he went down easy after that.
1) I found the story to be lacking and it didn't hold my attention whatsoever. It felt like I was just going from region to region and I found myself barely understanding which new lord I was dealing with and for what reason etc .
2) I also found the inventory system especially late game/close to the platinum to be tedious and exhausting. The repetitive process of sorting through, disposing of, and selling a lot of equipment I didn't need, resulted in a lot of frustration for me. I liked a lot of the character designs/graphics and the challenge of the game, but I'm hesitating starting the second one because of the overall lack of enjoyment of the things I just mentioned.