I have only once seen a port get burned out (2014 MBP 13" SD Card slot), and that was because the user was using the card slot as a permanent external storage.
The USB-C ports on these computers are pretty hardy and can take a lot of I/O usage. There are lots of people who use Caldigit or OWC docks which can support 6 plus devices and I haven't seen any reports of issues with the USB-C port(s) burning out. I personally use a Caldigit dock which powers my 2017 MBP wTB, has two external displays and two external hard drives plugged into the dock, all plugged into just one USB-C port on my machine, and I have not had any issues at all.
My main suggestion is buy a dongle or dock from a reputable brand name you recognize. Cheaper brands are more likely to cause issues and possible mess up your computer's I/O ports. Often times the cheap brands aren't even to spec for proper USB-C safety standards.
I would aim for brands such as Belkin, Anker, Hyper, Caldigit, OWC brands. They cost a bit more but are more reliable and safer for you computer and your external devices. The one you listed on eBay I would hesitate on, as it doesn't even list the brand name.