My elderly in-laws have a couch that allows you to sink deeply into it when you sit. Because of their physical infirmities, standing is difficult. The frame of the couch is in tact. None of the frame is broken or drooping. The cushions look fine, but I'm sure they have lost some of their support. My theory is that the springs supporting the seat cushions are worn.
Assuming that my theory is correct, does it make sense to try to get the springs replaced? Is there a snowball's chance that a furniture repair person or an upholsterer would be able to replace the springs? The sofa is not a sleeper version. It's just a sofa.
The couch is in great condition otherwise, and the in-laws are not amenable to buying new furniture. Any thoughts?