Mac mini is priced at a price, in addition to many people's entry Mac, it is the choice of some high-end users. But for the average person, the Mac mini has to add more. USB Port and SD Card Reader will use the Hub.
A company called Satechi has launched an aluminum Hubs for the Mac mini that can be used by connecting Thunderbolt 3. It includes one USB-C port, three USB-A ports, and a 3.5mm headphone jack.