Why is "no tax funding" a hard requirement? I would think the lowest cost to get that market information publicly shared and forthcoming (and thus increasing the efficiency and effectiveness of the market), would be for a government dept to operate the frontend distribution, but require regulatory submissions of transaction data within reasonable latency windows. It's just a modern form of say US SEC document submissions and EDGAR to distribute.

It's because why should taxes fund things that benefit rich people? It's not far off from taxes funding the caviar at Davos.