Solutions to the problem have been proposed since at least 1982. if you wanna get theoretical Bitcoin isn't even a game-theoretically unique

In fact that's probably the biggest criticism in general of the technology. What does it solve? I can't really think of a single use-case that couldn't have been solved using other, existing technologies. It seems like it's just adding extra constraints with no actual benefits. And it never lives up to the supposed benefits. In terms of centralization that's turned out to pretty consistently be a false promise. One Bitcoin transaction uses about as much electricity as a US household uses in a month so it's not scalable or sustainable. The cryptography techniques aren't particularly novel except maybe the way they were put together. But you can usually get a lot more use out of just using those cryptography techniques without all the added baggage. The idea that it provides anonymity is also very false. If anything, quite the opposite.

The one thing it does somewhat well is introduce scarcity where there previously was none. Which is often a major cost rather than a benefit but even when it's the main benefit it's not really an effective tool (see all the examples of non-tech-literate people buying "NFTs" as art and then finding that that encrypted URL they just bought got taken down)