Regional airlines stopped doing regional flying 10 years ago.
Customers want:
Full size seats
lay flat seats
2 or 3 lavs
free drinks
free food
frequent service
free bag check
seat beside them empty
choice of window or aisle
f/a that they can abuse
like to travel safer than in a car
wheelchair service
special services

All for $99.

If you want a cheap ticket then something is going to have to give. And that's services. i.e. extra lavs.