Who gives a shit about whether the human eye could have made the decision? That's literally the point of VAR, to see what the human eye missed. Yes there are people still debating it because some people will do that regardless of a line being drawn and a guys leg literally being on the other side of it. Have they plucked that line out of their arse, or do they have a computer that can 3D model where the players shoulder is and therefore accurately draw the line? Probably the latter, but I guess they never explicitly tell us.
A lot of peoples complaints are with the actual offside rule, not VAR. As soon as it goes to VAR, they have to back their technology to be either 100% right or not, they can't let some bent pigmol **** see it's offside but arbitrarily decide whether they think it's far enough offside to warrant following the rules or not