The cheap ones use very simply analog transmission techniques to send a video image. The quality is just enough to see where you’re flying the drone, but it’s much less than you would expect from a security camera.

There are digital options available but once you price the digital transmitter and receiver it’s going to be in the hundreds of dollars, not low tens. Amazing that it’s as cheap as it is, but there’s still a price.

The parts you linked are just cameras, not analog transmitters. It’s a cheap camera sensor with just enough circuitry to get a low res analog signal out.