Today i researched why my ESXi 7 based virtualization host didn’t accept my second, Realtek RTL8125 based, network adapter. Contrary to the primary one, which is Intel-based, there was not sign of detection in the hypervisor. Unfortunately i then found that - contrary to what i had in mind - VMware actually does not feature any Realtek drivers. Also the drivers that worked until ESXi6 will not work on ESXi 7 as the architecture for the drivers (vmklinux) has changed.
Quite sad but this hopefully ends your search a bit earlier than mine.
The solution is either to use an Intel-based network card (avoid early i225 chipsets, use at least v3 or better the i226) or to use a USB-based network module and the VMware fling for the USB based adapters. As VMware has shutdown the original webpage after the aquisition by Broadcom you can either download the drivers from the Internet Archive or try the link via Broadcom .
Or alternatively get rid of ESXi and move to e.g. Proxmox.