Learning to play the guitar or code also doesn’t have a difficulty slider, but people of all abled-ness manage it anyways.
Games are about entertainment. They're not a career. Nobody is paying me to play a Fromsoft game. More importantly, nobody is gatekeeping the entertainment, immersion, and story of music or coding behind me being able to "Git Gud".
And let's look at music and coding. Since I can speak a bit to both. For music, OF COURSE there are difficulty sliders. When I took recorder back in school, they had 2 different versions of many songs. When I first learned Christmas music on piano, I learned special "simplified" tracks for the songs. I never "Got Gud" at music, but I still got to the end of the book.
And coding. Coding is the opposite of a Fromsoft game. You're surrounded by mountains of tools that try to make it easier. When I bring in a junior developer, I'm not giving them some unforgiving code challenge to power through. Maybe they'll never be good enough to design a specialized cache or optimize queries. So I give them the things they CAN do, and hold their hand so they always succeed. Junior devs don't ever fail, not because they "git gud" but because I set them up to succeed by this little difficulty slider called "how hard is this ticket to do and how much help do they need from me?"
A waitress can get fired for getting caught withholding a cash tip from a tip pool if they have one. Hell, we even needed to have a law to prevent restuarants from taking the tips for themselves.