DJI drones are the industry standard because they are very good and typically cost significantly less than non Chinese manufactured drones. I can't currently substantiate this claim with data, but I would be shocked if less than 80% of commercial drone flights in America used DJI. I think the actual number is going to be in the 90%+ range.

There is one American company making comparable products, https://www.anzurobotics.com/. If I understand correctly, these are basically DJI hardware with American software. I don't know if they use DJI control boards or manufacturer their own but their FAQ does mention they license tech from DJI.