No, because money such as the dollar, besides being traded on the market, can also be used for returning it to its issuers - banks for satisfying loan or bond debt that was created by putting the dollar on the market. Money such as gold, besides being traded can also be used as jewellery, an electroplated coating, dental restorative material, etc. So, no, money is not useless. Only Bitcoin.
BTC is a digital currency, it does not have centralized issuers like fiat, neither is it a physical coin that can be forged into another thing of value, and so on that basis you conclude that it isn't useful. I don't know what's your own definition of use case, but to anyone with understanding, BTC is useful and has its own use cases, some of which i am sure you know of, but you just seem to be trolling here.
So, what anyone can do with Bitcoin besides selling it to someone? Currently, you have the whole army of holders. You have masses of people who bought Bitcoin. What can they do with it besides transferring it to other market participants? Or take the following thought experiment because you Bitcoin supporters love to compare Bitcoin to fiat money:
Suppose you hold all the issued dollars and bitcoins. Question: what can you do with them without selling them on the market?
Let's start with dollars. The dollar is debt owed to banks. It goes into circulation when commercial banks issue loans to individuals and companies or when the Federal Reserve purchases government bonds. Consequently, the banks take it back for paying those loans and bonds. So with your dollars, you can benefit millions and millions of people by repaying their loans and removing liens on their cars, houses, land, etc. Also, you can repay government bonds subscribed to by the Federal Reserve. In that way, you can benefit taxpayers. An item that can benefit so many people without being sold on the market is obviously useful.
Let's now go to Bitcoin. So you hold all of its supply, which is around 19 million bitcoins. You hold virtual coins that were advertised as being fast, secure, immutable, decentralized, scarce, liberating, etc. But what can you do with them? Well, literally nothing. That anonymous guy Satoshi Nakamoto who put them into circulation via his protocol is not like banks. He doesn't take back issued coins in exchange for some benefit, such as removing a lien. Bitcoin, unlike the dollar, is not debt. So essentially, you're left with just watching the number 19 million on the screen. You have something that everyone can have in an instant by pressing keys on a keyboard. As no benefit can be derived from that, your holdings are totally useless.