Well some companies still undercut their pilots as a whole while still paying based on the size/seats of the airplane. Yeah Atlas underpays but a 747 captain still makes quite a bit more than a 767 captain.

Same thing at JetBlue for another example. A320 pay is under market value pay compared to the legacies but you still get paid more than a 190 pilot.

My point being, if you do make it to the mainlines, don't be surprised if your regional 737 flying is paid a lot less than international 787 flying for the same company.