The vast majority of TV Networks shows are made by the studio that owns the network
Studios don't own networks. Studios make programs. Those programs are distributed through distribution companies to stations.
Due to corporate consolidation, it has become common in recent years for a big corporation (Disney, for example) to own a production studio, a TV network, and a distribution company. But they have to exist as independent entities from each other.
Because of common ownership, bundling deals, and audience expectations it is common for a TV show to stay within a particular corporate parent, but it is not alway the case. There are a number of TV stations in the US that air content from two or even three of the big four networks.
That's why at the end of all the network entertainment TV shows you see the distributor listed. It is a separate company.
Studios don't own networks. Studios make programs. Those programs are distributed through distribution companies to stations.
Due to corporate consolidation, it has become common in recent years for a big corporation (Disney, for example) to own a production studio, a TV network, and a distribution company. But they have to exist as independent entities from each other.
Because of common ownership, bundling deals, and audience expectations it is common for a TV show to stay within a particular corporate parent, but it is not alway the case. There are a number of TV stations in the US that air content from two or even three of the big four networks.
That's why at the end of all the network entertainment TV shows you see the distributor listed. It is a separate company.