Jesus didn't die on an altar anyway.
There was no altar at the Last Supper, they were reclining at the dinner table.
Altars are only for offering actual sacrifices. We don't offer the sacrifice of Jesus to god for our sins. He's not some thing we manipulate like that.
Jesus gave Himself up for our sins. He laid down His life on His own to take the punishment for our sins, dying in our place.
To treat Jesus as if He's some kind of animal to be brought to God by us to be slaughtered for our sins denigrates Him terribly. What an affront to God.
Very well stated...thanks!