Money is a technology. Its purpose is whatever use you want to put it to.

Like any technology, a money system can be designed so that it works well enough for a small set of intended purposes, and poorly for all other purposes. Moreover, its uses can be constrained by laws.

I think an open question is whether existing laws related to money or property apply to cryptocurrencies. For instance, "theft" and "fraud" cover a lot of things, without specifically listing all of them.

If it's ambiguous whether such laws apply to crypto, then sure, someone could use the legal system to settle the matter. In fact, using the legal system to remediate undesired transactions could be as good a use of crypto as any, if "anything goes."