Is there anything in the vault formula that makes it less likely to give you gear peices you already have and more likely to give you peices you do not? Because that would be great.
Rumors that there is.
In the early Shadowlands Beta, the Vault was notorious for giving duplicates. Like if you have a high item level 1H weapon, sometimes the Vault gives you 3x 1H weapon choices (none is useful), which was too discouraging.
Later Blizz added some algorithm that greatly reduced the probability that the Vault giving you non-upgrade items.
I speculate that if you have relatively high ilevel, then occasionally you can still get non-upgrades from the Vault. But if you are new and still catching up, then the Vault wonât be giving you non-upgrades.