It certainly could but with awful performance. This is just a proof of concept and no one should do this save to experiment with low level Ethernet. You're far

It certainly could but with awful performance. This is just a proof of concept and no one should do this save to experiment with low level Ethernet. You're far better off starting with a micro controller that features USB and Ethernet built in, of which there are MANY. If you want Ethernet on your pi pico, use an SPI Ethernet controller such as the Microchip LAN9250.