A better term would be #1 target. As we know, Brady had Gronk and Pat had Kelce. They aren't WR, but they give the same benefit as a #1 WR.
A true #1 target is someone another team has to scheme for. This person is open even when they are not open. Contested catches, reliable week in and week out. Routinely beats their coverage. They are going to get you 1200+ yards and ~10 TDs a year.
Is there even any examples of this actually being done?