why haven't ethernet connectors changed?

I was looking at a Raspberry Pi board and was struck with how large the ethernet connector is in comparison to the board as a whole. It strikes me: ethernet connectors haven't changed that I'm aware in pretty much 25 years. Every other cable has changed several times in that time frame. I imaging that if anybody cared, ethernet cables could be many times smaller. Looking at wiring closets, etc, it seems like it might be a big win for density too. So why, oh why, nanog the omniscient do we still use rj45's? Mike