(Though actually I think that drivers' license limit is based on the vehicle's maximum loading, so probably even skinny passengers wouldn't save them.)
UK common driving license (cat. B) seems to be similar to other EU licences (Spain here) I guess because previous EU standardization.
"Category B" licenses (post 1997): "You can drive vehicles up to 3,500kg maximum authorised mass (MAM) with up to 8 passenger seats." [1]
0: "When loading cargo, always consider the vehicle's Gross Vehicle Weight Rating (GVWR). The GVWR is the maximum allowable total mass of the vehicle including all passengers, fluids, and cargo." https://www.tesla.com/ownersmanual/cybertruck/en_us/GUID-12A976DD-EB60-431B-AFF1-5A37E95006DB.html
1: https://www.gov.uk/driving-licence-categories