I have roads with no cars, cities with no people, and oceans with no boats. Hopefully this riddle isn't lost on you

In a physics world, maybe I’m plucked or maybe im pulled apart in a cheesy way

I hang from outlets like a tired vine, feeding phones one bar at a time.

In your line of sight but remain unseen, I can be a blade-like bridge that is sharp and clean, Or roundly sweet and cute as a button I am a filter and a detector of things delectable or rotten.

In a circle, I am the divide, A part of the whole, where secrets reside. On a board, I'm a cut of delight, In a pie, I'm a sharer's delight.