Celeste, another famously hard game (that incidentally I used to speedrun and am wearing a tshirt of right now) has "Assist Mode." (which I now see was mentioned downthread) When you select it from the menu, it states:
> “Assist Mode allows you to modify the game’s rules to reduce its difficulty. This includes options such as slowing the game speed, granting yourself invincibility or infinite stamina, and skipping chapters entirely. Celeste was designed to be a challenging but accessible game. We believe that its difficulty is essential to the experience. We recommend playing without Assist Mode your first time. However, we understand that every player is different. If Celeste is inaccessible to you due to its difficulty, we hope that Assist Mode will allow you to still enjoy it.”
Well, more properly, that's what the initial version said. There was a lot of discussion in accessibility circles about this; it was clear that they had their hearts in the right place, but it was still a little ... condescending is too strong, but a little too judgy, maybe.
When they released Chapter 9, it was updated to instead say:
> “Assist Mode allows you to modify the game’s rules to fit your specific needs. This includes options such as slowing the game speed, granting yourself invincibility or infinite stamina, and skipping chapters entirely. Celeste is intended to be a challenging and rewarding experience. If the default game proves inaccessible to you, we hope that you can still find that experience with Assist Mode.”
This is still an options/settings style solution to this problem, but the way it's framed is significantly different, and the options are fairly granular, so you can tune things as you wish.
Incidentally, Maddy, the game director and one of the devs for Celeste, had a Twitter thread about what she would imagine an Assist Mode for Sekiro might look like: https://twitter.com/MaddyThorson/status/1113534763564826624