What do you do with an old piano?
Tens of thousands of new acoustic pianos are sold every year in the US. While this may sound like a lot, changing domestic norms and the development of electronic pianos have brought acoustic piano sales down from many times that amount a few decades ago. Peaks of over 300,000 piano sales per year in the US were hit in the early 1900's and again in the post-WW2 boom.
One thing that has not changed: pianos do not live forever. And eventually, usually decades after they are bought, they have to be disposed of somehow. The chances are, you have stumbled across this page because you are trying to figure out what to do with an old piano from the boom years many decades ago that is now past any musical life.
Don't be discouraged by this - no manufactured object lasts forever, and most fall to pieces or stop working much more quickly than an acoustic piano. I still regularly service pianos...