The Trojan Room coffee pot camera existed before the web existed. Before the web it was a client/server protocol on a local network. They only made it into a webcam after the web was invented and started supporting images.

What I remember is that when the first web browsers capable of displaying images were launched, people found a way to sample a single frame from a camera and load it into an image tag to get an extremely slow frame rate camera. People had been trying to make video calling a thing since the 1960s, and I think the first "webcams" were new attempts to demonstrate that. They basically came out at the same time as XCoffee being available on the Internet, but they had more publicity behind them. IMO, what made the coffee pot special was that it was so clearly useless to everybody except a few people in a lab in Cambridge. It was revolutionary that bandwidth and camera hardware was so cheap that someone could allow anybody on the planet to just check out the level of their coffee machine on demand at any time.