I really wanted to like Sekiro and gave it more than a few fair shakes. In the end, it felt too punishing for me in my current stage of life and I just don't think my skill level and patience were up to the demands required to feel like I was making progress. Keep in mind, I'm very hyper-critical of the "Souls-like" genre on the whole and if I like a Souls-like game, it's in spite of its difficulty. I appreciate challenge in games. I even don't mind replaying portions of a game to "master" it, to an extent. I remember how beating Ninja Gaiden on X-Box felt like one of the greatest accomplishments ever. But that was...damn...18 years ago and these days, games have to give me a reason to want to come back to them, either by rewarding my effort or by at least acknowledging what it demands of the player. Sekiro has a very fascinating world and setting...but I couldn't see much of it because it kept putting up walls for me to beat my head against until my vision was blurry and my head was hurting.
Take all that with a grain of salt or two.