A lot of people use their laptop as a desktop replacement and kinda leave it in one spot or only move it between two spots (home desk/office desk) rather than as an actually portable take anywhere use anywhere situation
While a regular usb-c ethernet adapter has a flexible cable between the laptop and the bulky rigid part.
The current crop has been great for my needs — a couple models have 10G Ethernet built in (CalDigit is the one I'm using now), and most now have more than one Thunderbolt port that allows a high speed storage device to be used as well (in addition to a 5K or 4K display or two!).