It may be a pain to only use one connector, but the protocol itself compared to a lot of external busses is a lot nicer. One of the big things ethernet gives is a lot lower latency. The ear is pretty latency-sensitive, with voice latency of 15 milliseconds being a threshold where most people can start noticing. Because of the polling nature of USB, you've got to wait for the bus to ask for data, which means you're going to have at least a couple of milliseconds of latency. Also, because Ethernet is a many-to-many protocol, you can do things like have the synchronization clock on the same connection as data, so you don't need to run a million clock cables along with your data cables.

Sure you don't have that backwards? USB 2+ has isochronous transfers with guaranteed bandwidth and latency that come with guaranteed start-of-frame timing strobes every 0.125ms with a jitter spec much better than that. Ethernet... doesn't.

It depends on the type of USB audio device. USB MIDI devices, for example, use bulk transfers because they need reliable communications to handle things like sysex sends. Additionally, Ethernet, through the AVB suite [1] does have time reservation, synchronization, and other things that are very useful in dealing with realtime data.

[1] https://en.wikipedia.org/wiki/Audio_Video_Bridging

> Because of the polling nature of USB, you've got to wait for the bus to ask for data, which means you're going to have at least a couple of milliseconds of latency.

That's up to the driver. USB 2.0 can poll at up to 8kHz. USB 3 is harder for me to find exact numbers on but it has more flexible timing and can go even faster.

Most professional workstations will have at least two ethernet ports. Heck, I've got mITX machines with two ethernet ports.

The other thing I've seen ethernet repurposed for is transmitting HDMI or USB between special transceivers so you can have your PC widely separated from I/O devices. It was a standard approach before Steam Link became a thing.

One of the nice things is that you can get comparatively long runs of ethernet cable without any special equipment. There's absolutely no problem doing 100ft+ runs of CAT5.

It's not only about the connectors. With ethernet(avb or dante) you get networking audio(ip based) and time sync over long cables. This is not really possible with USB, jacks, firewire etc. A single ethernet connector may have hundreds or thousands of audio channels but then you are right that a switch is required to split them so the low number of connectors may be an issue in some cases(unless you are willing to buy a switch)

With avb/Dante you get up to 128 channels of audio over Ethernet. If that isn't enough, you can add quite a few more give ports via thunderbolt.

The big practical advantage of Ethernet is standardized cabling, connectors and tools.