Lockdown showed it worked on a temporary basis. It did not show that such a plan would work for all or most sectors permanently.
One of the really notable things in the responses to me is that those claiming that WFH is just fine seem almost always just to be thinking of their own specific job duties. They don't seem to be considering the wider, and less measurable, elements - things like mentoring new workers, or the creative synergies involved in developing new products or programming, or developing relationships with clients. Things like this are important, and in many sectors actually vital to the ongoing viability of the business.
With disability, employers have two obligations. The first is to consider whether a position contains really unnecessary elements or could be arranged in such a way that an employee can totally fill the role, just like someone without the disability. Maybe this might mean investing in some software that allows the employee to listen rather than read text, just as an example.This is really an ideal kind of situation - the employer has no real downsides and someone gets a job.
The other is asking for accommodation, for the job to be modified to make it suitable for whatever the limitation is. Working from home is like this - it might be that the core elements of the job can be done perfectly well at home by a diligent employee. But there also will be sacrifices from the employer - that person might not be able to meet clients at the office for example, so that part of the job will need to be done by someone else. And training new employees, helping them settle in, and mentoring, probably won't be possible.
That may be fine, and I think employers should try and accommodate this kinds of things if they can. But it only works if there are in fact other people in the workplace who can take on those roles. Just as an example - one of the tech teams in my workplace has an employee with an accommodation - he can't do listing or carrying and has significant mobility issues. Recently, another member of the team asked for a similar accommodation - but the fact is, that would leave the team short of people to do what is a significant part of the job.
Should the limited ability of workplaces to accommodate people with significant disability be spent on people who just don't like to have to see other people, or even families who don't have good childcare arrangements? I don't actually think that's a great idea.