Fuel tank sending unit ground strap
Next question.......why is the sender connected to the line with a rubber hose? The tank and line are solidly attached to the underbody. tmm
The rubber hose makes it serviceable if nothing more. Consider there is also a rubber hose between frame mounted hard line and fuel pump. Anywhere the is potential for movement a flexible material is required. Maybe the fuel tank doesn't move when filling and emptying. Betcha those straps would let it move in a accident.
As for the ground strap and what I stated about the rubber components isolating the sender, The retainer spot welded to the tank that the lock ring sits under is not flat or continuous.
All these parts are galvanize coated and just laying against one another. Even a ring terminal with a screw through it has potential for failure.
Their ground path through a daisy chain of parts has proven insufficient everywhere including inside the cabin where environment isn't as great a factor. The fuel sender, like the ground jumper from engine block to firewall, are spots where their engineers recognized a potential fault and took a extra step, spent another dime, however you want to look at it.
Bottom line... If your particular car doesn't need the ground strap today.. Put it in the glove box or somewhere it can be found if/when you do need it.