There is a miniature version I think it’s called quadrax. Just too expensive but consumer applications
https://www.cnx-software.com/2024/10/14/wiznet-w55rp20-evb-pico-board-features-w55rp20-sip-with-w5500-ethernet-controller-and-rp2040-mcu/
We have gone from giant USB-A to the slim USB-C and converters are available. We have mini Display Port and converters are available. Why has no one tried to miniaturize RJ45?