What will happen to people who are too disabled to work if the government reduces their money?

I keep seeing articles about the government wanting to reduce disability benefits to encourage people into work. But what happens to those who absolutely can't work?

And how will disabled people who can work get over the systemic barriers such as discrimination? Is the government going to tackle that or is this just a cost saving exercise?

Does reducing disability spending save money in the long run or is it a false economy that causes losses elsewhere?