Why do municipalities have contracts with cable companies?

Townships and boroughs frequently strike franchise agreements with cable companies, allowing the for-profit companies right-of-way access to public and private land, meaning they can build and maintain their networks in exchange for payments to the municipality and other considerations. Gettysburg Borough offers a brief explanation on its website:

Franchise fees are governed under Section 622 of the Cable Communications Act of 1984. Section 622, states that municipalities are entitled to a maximum of 5% of gross revenues derived from the operation of the cable system for the provision of cable services such as Public, educational, and government access (PEG) TV channels.

A recent example is the cable franchise agreement that was up for a vote recently in West Rockhill Township. It states:

Generally, this renewed Agreement would continue to grant Verizon the ability to construct, operate, and maintain a cable system within the public rights-of-way in the Township, require Verizon to pay an annual franchise fee of 5% of its annual gross revenue to the Township, and obligate Verizon to provide reliable cable service and customer service to any location in the service area of the Township who desires cable service, among other things.