While public radio (APM, NRP, PRI, PRX...) offers a unique news and information format in many markets and music formats not otherwise heard in many markets, public television does not. We no longer need public television.
(1) PBS produces nothing. It's a distribution service only. Content comes from independent producers (like CTW) and from various member stations (WGBH, WETA, WNYC). PBS is a bureaucracy, a building and a satellite dish. Today's technology offers better, cheaper ways to distribute shows.
(2) Public television programming is redundant. Types of programming once unique to public television have become whole cable channels. Kid's channels. Channels devoted to history documentaries. Channels devoted to British shows. Channels devoted to pretentious talking heads. Originally, public television and PBS were envisioned as a fourth network, in a world of three networks and their affiliates (plus a few indies) with each of them doing lowest common denominator programming for the largest mass audience possible. That world has ended.
(3) Public television has totally debased itself. It began with pledge drive begathons. Now the process has expanded with Lawrence Welk and other old music nostalgia shows and informercials with somebody hawking "solutions" for health, diet, exercise, financial planning...
There's no longer a need for public television, in general, and even more so for PBS specifically. All any broadcaster needs is a high-speed commercial Internet connection to download programming. PBS' satellite is no longer needed.
For the record, PBS does not have "affiliates." Nor O&Os for that matter. It was deliberately set up with a completely different structure than commercial networks. Same for NPR. And read the credits on public television shows. You might be surprised at how much does NOT come via PBS.
Not every major metro area has/had a "PBS station" on VHF.
LA, Chicago, Washington, Detroit, Tampa, Miami, Orlando, Cleveland, Pittsburgh and Charlotte in the top 25 markets have/had public television on UHF. Go further down the list and it's mostly UHF. Not that this distinction means much any more. When public television was thought up (to replace "educational television") in the late 60s, public television was an after-thought.
For information on local public television shows, probably best to go to the local TV board.