It's never been feet since the offside law was first introduced. Why would we want to change it to that now?
Because we didn’t have a way of verifying anything regarding offside before VAR. It’s literally impossible to make a tight offside decision in real time. Your eyes need to look at least three things simultaneously - and then interpret whether the ‘interfering with play’ box has been ticked.
So if we have VAR, we should use what it’s capable of - which doesn’t include drawing lines from someone’s shoulder to the ground to compare against someone’s foot tens of metres away. Lens distortion, low resolution, low frame rate, limited angles are all huge roadblocks to the current system being reliable.
It should be where the feet are planted, it's football ffs. This elbow/armpit/boil on the bonce is an absolute pile of crap
I think this is closer to the solution than what we’re currently using.
As someone else said also, the only thing we can fairly compare are two planted feet on the turf. They are on the same plane, at least.
But even then, depending on where a player is in their stride, a planted foot could be behind or in front of them.
It’s a minefield. VAR has let the genie out of the bottle, and no one has a clue how to use it fairly and objectively.