I think most people with Cessna 172, PA28 type aircraft choose to manage their own maintnance. Larger aircraft with the possibility of public transport type operation probably elect to have their aircraft managed by a CAMO.
In the early days quite a few people registered to start a Part G as this was a shuffling paper operation.
In my opinion I would opt for a co-located Part G & F as this is probably cheaper option for an owner..