Earlier quoted context omitted.
Wireshark is great but it does not show you every byte the network carried. For example it never shows Ethernet preambles, only sometimes shows Ethernet frame checksums, and never shows interpacket gaps (which are a required part of the Ethernet protocol). So yes it comes close but it just goes to show you, there is always more detail hiding somewhere!
Are the Ethernet frame checksums even visible to Wireshark, which hooks into the IP layer? would some of the ethernet stuff be only visible within the ethernet card itself, not to the software stack?
See eg this bit about wlan for some of the complexity: https://wiki.wireshark.org/CaptureSetup/WLAN#link-layer-radi...