Some flavour of Ethernet digital audio are used quite often in tours/live sound use (huge venues use this or sometimes MADI or even more exotic flavours). Ethernet snakes typically use some variant of this (check out Allen & Heath’s live stuff for instance). I don’t believe many (any?) pro tours route the audio in analogue form back to the mixing console anymore.
Usually in those configurations each device’s channels are preconfigured for that tour setup and it’s clear what’s where using naming and presets.
This allows the FOH and the monitoring/foldback engineer to both get a copy of, e.g. the guitarist’s signal and do what they need to with it, without having to daisy-chain the desks.
I think you’re mostly thinking about small clubs/venues where the venue’s desk and PA are utilized. In those cases the analogue route is, of course, most common, but that’s rapidly changing for the higher end locations - digital snakes are affordable now and it’s not uncommon to see the FOH engineer walking around mixing with an iPad in some places. This seems to be the major trend in live sound and I wouldn’t be suprised to see it become equally common with all-analogue setups in a few years, except for places that just don’t care about their sound or have zero budget.
Edit: To clarify, there are lots of “standards” for this right now - the market needs to sort this out before any of them will be really viable. AES50/67, GLD, Dante, AVB, etc. Multiple Ethernet standards, but not all use TCP/IP or UDP style protocols and not all are compatible with standard Ethernet routers/switches.