The only regional that ever operated the EMB 190 was Republic while BB was trying to play big boy airline CEO. Southwest absolutely castrated BB and put him back in place. Those 190's are almost all gone now, except for a handful doing some charter crap. They'll be gone by the end of summer. No mainline scope clause allows anything bigger than 76 seats. Over the next few years, more flying should return to mainline as regionals wither and die due to lack of cheap labor.