Robinhood's behavior shows why blockchain-based finance, with its censorship resistance and permissionless participation, is the future.
It's already the case that many of ethereum's DeFi apps can't betray users.
Unlike a centralized financial institution, a DeFi app's smart contract code can be shown to be a public API that treats all users fairly and correctly, with no admin keys or back doors.
Smart contracts can fail for other reasons, such as bugs or bad economics. But, what they can't do is call up their friends and ask them for some favoritism.
In DeFi, we say that smart contracts that can't betray users are "credibly neutral". https://nakamoto.com/credible-neutrality/ (by Vitalik Buterin)
As an example, one important DeFi app that is credibly neutral is Uniswap, a decentralized trading exchange that did $700M in volume yesterday. The main Uniswap app is here https://app.uniswap.org/. Financial stats for Uniswap are available here https://info.uniswap.org/. Yesterday, Uniswap made $2M in fees for its liquidity partners (anyone can provide liquidity). Fee data can been seen here https://cryptofees.info/.
Many tokens on Uniswap are pump-and-dumps or projects that won't succeed. Anyone can list any token. Yet, users seem to love the control and reliability given to them by Uniswap and other DeFi apps.