Speaking as a disabled person, it seems to depend highly on how much support you receive from those around you, not just family and friends, but institutions too. That's my honest answer, the people who have a soft place to land and top of the line support will just fare better. Also, how long you've had that support matters too. A sense of security and stability is key when you know you might not be able to survive on your own. Of course, it also depends on certain factors like overall quality of life, and how well your pain is managed if your disability involves chronic pain.
The peak of suicidality for me has been feeling trapped and not having proper pain management, ways to support myself, and not having a stable place to live. A lot of the homeless people you see have some sort of disabling health condition that prevents them from holding a steady job, and have been abandoned by their families and society at large. Especially if one is disabled by what others perceive as a mental illness/can't be seen with the naked eye, the pittance of sympathy seems to run out. With proper support, way less people would feel such stark hopelessness.
I implore you to read a book called 1 liter of tears, it's a real diary written by a young girl with a progressive neurodegenerative disease. Even though eventually it would paralyze and kill her, since she became ill at an early age her parents and doctors taught her to "fight" it and tried to keep her independent for as long as possible, she was determined that she would one day walk again and recover, even if it was physically impossible.
The reason why she had this attitude was because her mother imparted it hard onto her and her family worked tirelessly to find the best medical facilities and resources that could support her, plus she'd always had a very normal and happy life prior to her diagnosis. She went to a special school designed for children with severe physical disabilities, and had a very happy demeanour and spirit until the last couple years of her life when she could no longer speak or move, and all her friends stopped visiting her.
Even if the material of the book may not be relatable to you personally, it gives you a glimpse into the psyche of a person who heavily valued their life and continued to fight against the burden of being severely disabled because of that, as well as the pressures of living in a collectivist culture where there is a heavy emphasis on fighting for life/accepting the pain of one's life in a stoic fashion so that they can fulfill their role in society.
Before you experience permanent health issues firsthand, which is something many people don't encounter until old age, it's a bit easier to witness other's struggling and think, "I could never handle that myself." It's a very different story when it becomes your normal, everyday life. A good chunk of my childhood was spent assisting in the care of my aunt who was disabled by a long-term, severe autoimmune condition. When I saw some of the ghastly procedures that she endured, the amount of pain she was in daily, the way that she struggled, had to live with less money and resources than everyone else, etc, I thought there was no way that I would be able to have the strength to withstand some of the things she did.
Now, since I was a teenager, I've been disabled by chronic health problems, in addition to the ASD and dyspraxia that I was born with. Facing that own situation myself made me realise how hard it is even if your quality of life is diminished to actually ctb. There have been times where I have been in so much physical pain I just want to die any second to stop it, and still can't do it. Things got worse and worse for me because I've had to push to function in spite of having health problems when many others don't and are supported by their families. It's a nightmare.
On the other hand, I have seen many people who are enjoying their life, in spite of dehabiliating health conditions, because they are properly cared for and dont have to push themselves to a breaking point, and have the financial freedom to do things that would make life feel fulfilling. Some people have disabilities that do not cause pain and can be easily accommodated for, and others have enough support to where they feel secure and hopeful. Everyone's situation is different and everyone has a different breaking point of what they can tolerate.