This is not necessarily the case if you are deprived of disability benefits so it is okay to have the hearing after rather than before. People with a disability may not be destitute. The courts will look at a number of things when they make their decisions about how formal adjudications must be conducted. Administrative cost and the administrative burden imposed on agencies do factor in. Sometimes the Justices will decide that some things are just so important that agencies must provide them despite the cost.
Most agencies start out with the least complicated proceedings and then get more complicated.
For example, if you are applying for Social Security disability benefits, you will have a paper hearing first. The decision will be made on the basis of written evidence you submit and what the agency requires. This could include written testimony from your doctor who has examined you for example. The next step up would be an oral hearing where you can actually appear and give testimony in person. Sometimes this is essential because many people, like those on disability or welfare, do not have good communications skills and their written materials may be very poorly completed.