I was fed up with all the cheap rubbish out there that needed a driver to work on Mac, or not even work at all when a new OS comes out. So done a bit of research and found out you want adapters with an RTL8153 chipset.

Here is mostly verbose info I found on some adapters I’ve had and what chipset they use. I’ll come back one day to make it cleaner.

RTL8153 (0x8153) - CharJenPro "premium" hub with USB-A ports (no driver, just works)
RTL8153 (0x8153) - Belkin USB-C to Gigabit Ethernet Adapter (Belkin USB-C LAN)
RTL8153 - Vention USB-C to Ethernet HUB - https://www.aliexpress.com/item/32875260609.html
RTL8153 - Generic USB-C to Ethernet - https://smile.amazon.com/Ethernet-Adapter-uni-Thunderbolt-Compatible/dp/B077KXY71Q?sa-no-redirect=1
AX88179 - ugreen USB-C gigabit ethernet (needs driver! none for 10.15 yet)
BCM5701 - Apple Thunderbolt to Gigabit Ethernet Adapter
@wolfies Check the chipset on the Belkin, I bet its one of those low cost Realtek USB ones that you can get otherwise for $10. The Apple Thunderbolt chipset is a Broadcom PCI-E one that is fairly high-end. Its an issue both with the cheap chipset and inherent limitations of USB. As you can see maximum bandwidth is not directly correlated with performance. – user71659 Nov 7 18 at 17:34 from stackoverflow or so..
Such a shame Apple (or anyone) has made a thunderbold (usb-c plug) to gigabit ethernet adapter yet :|

Note: You can find out the chipset used usually in lsusb or dmesg commands after plugging in the device. (in Linux/Debian)

I’m testing a bunch of adapters to see which works best on Mac.

More info on RTL8153 for Mac
https://gist.github.com/MadLittleMods/3005bb13f7e7178e1eaa9f054cc547b0

Belkin USB-C LAN adapter details from Mac info.

Product ID: 0x8153
Vendor ID: 0x0bda (Realtek Semiconductor Corp.)
Version: 30.00
Serial Number: BLAAA00000
Speed: Up to 5 Gb/s
Manufacturer: Belkin
Location ID: 0x01200000 / 1
Current Available (mA): 900
Current Required (mA): 256
Extra Operating Current (mA):0