Why does the DC area have so many bus systems? Would it be simpler for Metrobus to take over all of them?

Like you got Ride On in Montgomery County and Fairfax Connecter. Those counties also have DC metrobus service. I could see this being very confusing for users to have to track multiple agencies and it makes regional coordination harder. Plus some of the networks are free while metrobus isn't which could cause confusion for riders used to free buses when trying to take a metrobus somewhere else. I think metro should take over buses in Fairfax, PG, Montgomery, and Loudon counties. But I'm an outsider from Boston so I might be missing something.