> Networking has legacy reasons from the bad old days when byte order wars were still a thing, but those days are gone.

Yeah, this isn't true. Low level hardware receiving data still likes to use shift registers:

    * Zero shift reg
    * clock in one byte, shift into shift register
    * Clock in next byte, shift into shift register shifting the previous byte left one
    * Repeat for as many bytes as you have

If you want this to work for a variable number of bytes, then you need most significant byte first, so that everything more significant is pre-zeroed. This is not theoretical - we did this for an FPGA network offload thing last year.

Processors can't agree on endinaness, but network protocols have. "Network byte order" is a standard thing that is almost completely universal across communication protocols.