Does direct Ethernet connection improve sound over wireless for you?

[foFox]

These all are digital connectors, there is no difference between them, in terms of perceived quality *. This is why if you want to take information from one place to another, provided you have enough bandwidth, digital wins over analog, every time.
Software protocols running on top of networking hardware ensure error-correction, ordering of packets, low latency.

* Assuming there are no shenanigans happening in the source's operating system, and that phantom processes every input the same way.