I wish my project manager would understand this and face the fact that we're maintaining a 12-year-old application. Our application just can't do all the thing

I wish my project manager would understand this and face the fact that we're maintaining a 12-year-old application. Our application just can't do all the things the client wants in its current state and we have to keep grafting newer tech to it, and we end up with defects like a hydra.