Define a “power level” or a “tier” for each artifact, and when gifting an artifact, use the player’s experience level and other stats to calculate an appropriate tier to gift an artifact from. The only reason it feels bad to get Giantslayer is because you know you could have gotten something much more powerful but randomly didn’t; if the more powerful artifacts were simply not possible to get due to you not having the right stats yet, this might not happen as much.