E*Trade and Ameritrade followed suit:
https://techcrunch.com/2019/10/02/robinhood-e-trade-schwab-a...
https://techcrunch.com/2019/10/02/robinhood-e-trade-schwab-a...
https://www.schwab.com/public/schwab/nn/legal_compliance/imp... shows that Schwab sends less than 1% of orders to exchanges.