Take away Hannity or The Five, and they’d lose viewers. Likewise, O’Reilly draws in a lot viewers.
Hannity IS more popular than given credit for; NOT as conservative as I'd like, BUT...miles ahead of fence-sitter, non-conservative and political mercenary, the fake, phony, fraud Bill "for-the-folks" O'Blowhard.
IMO his time-slot and moderate political views gives him a huge advantage in ratings.
Otherwise, who is a real "conservative" at FOX other than Laura Ingraham and Monica Crowley?