I don't think that the idea of either free software or the semantic web were hopeless or that they lead to the dystopian hell. Open source was created due to a disagreement with the idea of software freedom. It turned out to be exactly what free software wasn't - a tool for exploitation. Similarly, the semantic web was easy to implement - except that the big tech saw it as a hindrance to profit. That lead to the blockchain web hijacking the web3 designation from it. That said, both ideas are still viable and still alive on a small scale.