The r8168 driver package is no more supported by Arch. This means users should use the r8169 driver from the kernel, it should work in most cases.
(r8168 is the Linux legacy device driver for some Realtek Ethernet controllers)
EndeavourOS ISO previously had an implementation where users could choose to switch to the legacy r8168 driver for their LAN connection if the appropriate hardware was available. This option was removed due to the legacy driver (r8168) is no longer being supported.
At the moment only the r8168-dkms AUR construction is possible.
The r8169 driver that comes with the kernel supports all relevant devices, so it should not be necessary under any circumstances to really need the r8168 driver anymore. If problems arise, you can try building and installing the r8168-dkms driver from the AUR.
