Sure, that's what would happen if buys and sells could reasonably be paired up. Robinhood/Apex could've just kept these buy orders open until it found a seller

Sure, that's what would happen if buys and sells could reasonably be paired up. Robinhood/Apex could've just kept these buy orders open until it found a seller at any price and closed unfilled orders at the end of the day. That would probably be less preferable to all involved as I doubt these people were placing limit orders.