If I may offer a counter-point, I’ve been the supervisor of an employee that was on leave with no expectation of returning to work. I supported their decision and made sure that they had access to our employer’s health benefits, medical and mental, and tried to help with placement opportunities as much as i could. Though as the supervisor I was not able to hire someone else to do the work while the employee, who had made clear they would not perform the job any longer, was still technically employed.