Thunderbolt capability (Dell Inspiron 5406)

So, the Dell Inspiron 5406 is fitted with an Intel 11th gen i7, which has Thunderbolt 4 capability; however, the USB-C port is only 3.2. So the question is: what's stopping it from being Thunderbolt? Is the system board missing a physical Thunderbolt controller chip? Is the BIOS blocking it? I can't seem to find a definitive answer.