What constitutes reasonable accommodation, both legally and morally?

Hi Everyone, OP here. I wanted to respond with some more context, since I opted for concise rather than comprehensive in the original question. I can see how my phrasing in the question came off as disgruntled or callous - it wasn't my intention.

Despite not being in a position of power in this situation, I do know most of the details because the colleague who is struggling and I have been brainstorming how to improve her work situation. She went through several rounds of negotiations with our manager and HR to try to figure out what accommodations could be made to support her, but none seem to enable her to contribute consistently because of the extent of her illnesses. She is already able to work from home 100% if necessary and we already have flex hours in place. She attempted to negotiate a lay-off for herself so she could take some time to recover and research something more in line with her needs, but the department wouldn't go for that because it would eliminate the headcount needed for that position. She has also looked at an internal transfer but isn't interested in anything that is open (as well as the lay-offs having decreased the number of roles available for her experience level), and she can't guarantee that she would be able to contribute effectively in a new job. When we last spoke, the only thing I could come up with is for her to stay in the position as she is and continue to take extended medical leave as necessary. She hates that idea because she is someone who wants to contribute, but we just can't see any way around it.

I asked the question because I am wondering if there are other clever things that companies have done to basically keep people productive and in the workforce rather than on permanent disability. I also find myself wondering at which point, if any, the company would actually be justified in terminating her. It's not an end I want to see, but if it's not illegal to do so, I could see it coming to that.

It's tricky because you're not really the person in an appropriate role to try to support this situation, but ideally the company should be working with the person to figure out how to balance their needs and the workload. While I don't think it's reasonable to have an essentially dormant role, I also don't want to judge the person too hard tbh because I'm not sure what steps have and/or have not been taken to support them. For example, if I have an illness that makes a commute difficult, but I'm not allowed to wfh, I'm going to look like I can never work when actually I could work if someone gave me a reasonable accommodation (i.e., wfh if the job duties are a good match for wfh). Maybe it's flex hours, maybe it's more check-ins, kind of hard to give examples without knowing the specific disability - but I do encourage that all efforts are undertaken to make it work, and it really helps if we replace ideas around "equal treatment" with "equitable treatment" for these kinds of situations. If all of that is tried and the work is still not getting done, that's when I think it's appropriate to consider whether this is unreasonable or even if the employee seems to want to complete the job duties in good faith.