How is Ethereum (an open source network) ultra centralized and without democracy compared to PayPal or VISA which currently account for a large portion of Patreon payments?
Users (non-devs) have agency through the software they choose to run. If mainnet was seriously affected by some attack, users could choose to migrate to a healthier network run by honest nodes. This agency happens with every hard fork: the DAO, but also the PoS merge.