Sorry if my question sound naive but would it make sense to connect the dongle to internet over wifi instead of 4G?

Reading the doc I had the impression that the wifi chip only serves as a hotspot, but what if I want to connect the dongle to my home wifi and use it as a home server, does it make any sense?

You can connect it to the internet using the wifi. I worked with these extensively over the last few years and have a few hundred that I need to sell.