Gotta love those people who argue over Ethernet cables, the dismiss WiFi that removes them completely from the equation. Or that are concerned about jitter on their Ethernet connections. They're still very confused about TCP/IP. FWIW, buffers eliminate jitter. If jitter is so bad that the buffers overflow, then there's a serious ssue with the network that would show up in the router management as dropped frames.
Unless you are serious about cobbling a streamer from a Raspberry Pi, and doing the associated bit-twiddling, just get a BlueSound Node. They're available for under $500 now, and a big step up from your current setup, and not that far behind the $3k to $5k offerings. Next get off of Apple, whether you move to Qobuz, Tidal, or Amazon UHD. You'll be very pleased.