Done that already, Terran linked it. It shows his actual DPS values as well as some other statistics to show how much variety he has in his kills. So one test might have taken 30 bullets to kill the target, but another test at the same distance might have taken 60. I think the largest disparity was nearly 100 bullets.
Technically not mathematical proofs, but I don’t think it’s mathematically possible to show if a character is OP or UP. There’s too many outside variables to consider pickrate. For example, Mercy will always have a high pickrate because people just like the character, Bastion will always have a low pickrate because people don’t like him. On that note, Bastion can stay F-tier, we’re not asking for him to be magically dragged into A-tier, we just want him to be consistent and playable.
We’re not asking that he be super useful on every map, just that he’s playable. I don’t like him on KotH maps, I don’t find him super useful there.