Matt Levine has explained that even before the fees going to zero, the fees represented a small percentage of brokerage revenues. Elimination of the fees had an almost negligible effect on brokerage bottom lines—certainly not enough to change their entire behaviour.

> Commissions are way down there; in 2018, they represented a bit less than 7% of Schwab’s net revenue.

https://www.bloomberg.com/opinion/articles/2019-10-02/the-tr...