I've never met a disabled person who plays this. Only people with "small" issues. But I can tell you I have colourblindness, and am unable to associate nouns to directions due to a type of motor-based dyslexia under any form of pressure (left\right, larboard\starboard, port\star, izquierda\derecha, rechts\links, 左\右). I'm not elderly, I just struggle with these things, to the point where I'm downright terrified of trying to get a driver's license. Because I know that the moment the instructor says "turn left", I'm going to either freeze or go the completely wrong way.
I know someone with actual dyscalculia. Her brain just refuses to work when maths of any kind is involved, including counting or recognizing numbers.
So when you give me an arena that's completely purple (E9S) or orange (P3S), I will struggle. And this game's colourblind shaders rarely ever help. In fact, the shader supposedly meant for me actually makes it worse. I can't tell shades apart either, so often I run to Marker C fully believing it to be Marker D until I take a closer look at the really, really ugly font the dev team chose.
Give me something with nouns as directions for incoming attacks (O11S), I will struggle. And no, changing the terms won't matter, because my brain just refuses to acknowledge directions have names.
Hell, simply giving me something that's direction-based or messes with spatial awareness and I WILL struggle (Zodiark EX, E10S's shadows).
But I managed to find ways around it. For colourblindness, either I do the fight and wing it if I can't anchor myself to any "tell". Or I rely on patterns if there are any.
I pre-emptively spend minutes on end memorizing directions beforehand so I don't screw up when the mechanic happens. O11 is exhausting because I feel like I need to memorize four directions and not just two, because the boss turns around and it flips... but I do it.
I also had to memorize and do a lot of mental gymnastics just to figure out the rotation part of Zodiark. And my static had to use clock positions to help me resolve the shadows in E10S.
The girl I mentioned? She can't handle numbers, but she does recognize shapes, so I made this for her. It's not glamorous, but you know what? It worked, and she cleared TEA with it. It actually helped her with Limit Cut.
The point is... yeah, people with disabilities, or just issues in general, exist. And it's not often that the game is helpful. Some fights are easier if you find a trick around them, others aren't. Even on easier content like MSQ instances, people may feel disoriented until they learn their personal trick. From the outside it looks no different than learning the fight, but from the inside, it feels like it's one extra step people have to take over everyone else to do what everyone else says is normal.
I'm not asking for content to be designed around me and me alone, but it does get in the way a lot when content specifically happens to hit that one part that I can't handle without some form of a crutch.
And the people who ask for there to be a bit more awareness would definitely appreciate it, and likely aren't the sort of players to be lazy and not try to clear content. They work harder, even on "easier" content because stuff messes with them, be it perception, logic, awareness... More so than it would a normal person. I've seen people who actually are lazy and refuse to adjust and waste 7 peoples' time. I had such a person on an old static, and let me tell you, it did not last long. No one was happy. And knowing that I worked hard to deal with this and make sure the fights could go as smoothly as they could, even if I needed to be told where to go by someone else, to then see someone not even bothering really stung. It's not an experience I take lightly anymore.