Earlier quoted context omitted.
10+/trade is going back to the early 2000s for the US. Now it's effectively 0 for most common trades. Here is Schwab for example: https://www.schwab.com/pricing If someone is a big options trader they can probably find a better per contract price out there.
How do they profit? There must be a cost somewhere? Another reply mentioned spreads - still a cost (you lose money when you trade).
They also earn some money from 'payment for order flow'.