Yes it’s true that true that public blockchains are often open-source but public blockchains can still differentiate themselves based on their technological advancements, features, performance, security, scalability, etc…. While the open-source nature allows for transparency and collaboration, it does not diminish the significance of technological superiority. I don’t think it’s fair to say say that no public blockchain can win on tech supremacy alone or that decentralization is the only moat. Things like governance models, community support, ecosystem partnerships, brand recognition, and network effects also contribute (although not specifically tech). I think this oversimplifies the factors that contribute to the success of a public blockchain.

Network effect comes into effect.

I think it’s also in the team who’s building it, as even if it forks and has a mediocre team it probably won’t get accepted as much as the original. Also having a great team will evolve the project to a better project.