Agreed. Its even worse as it fits into their entire business model to capture young unsophisticated investors. An experienced investor would make one trade and notice the order execution was off, however when you specifically target an inexperienced investor its easier to get away with the con
An "experienced investor" would neither care nor, most likely, notice anything about this. Mostly because "experienced investors" aren't in the business of day trading. But also because nothing was "off" here. It isn't the Robinhood customer that is harmed by this, but institutional investors who, by this mechanisms, are excluded from the services of these market makers because they present a different risk profile.
I worked in HFT building trading platforms and it would be virtually impossible for me to see order execution being off using retail tooling.
In fact it takes incredibly sophisticated infrastructure to do it. The kind of infrastructure you build if you are a market maker who would like to pay for order flow.
Even the SEC doesn’t have the capabilities to check execution rates for every order. They rely on audits of smaller subsets of the orders in historical reports.