money corrupts
This is exactly the reason that Proton became a non-profit:
https://proton.me/blog/proton-non-profit-foundation
Swiss foundations and their board of trustees are legally obligated to act in accordance with the purpose for which they were established, which, in this case, is to defend Proton’s original mission. As the largest voting shareholder of Proton, no change of control can occur without the consent of the foundation, allowing it to block hostile takeovers of Proton, thereby ensuring permanent adherence to the mission.
Just remember that Cloudflare decrypts and re-encrypts all your data, so they can read absolutely everything that passes through those tunnels.