@protoaddct This is where I always came down when I was running the card. Transmute Artifact is not as good as Tinker, so right away if we want to tutor an artifact we start with 1 Tinker. Next, we consider whether Transmute Artifact is better than Demonic Tutor. Almost certainly not, so we add DT to our artifact tutor package. Then we ask is Transmute Artifact better than Mystical Tutor? Well, given that we're running Tinker, probably not, so now we're up to 3 tutors.
Only at this point do I consider jamming a Transmute, and I'm skeptical even that is correct. How many more tutors can we realistically jam into the deck? I'm down with some build where we're just running counters and tutors and want to win with keyvault pronto - Turbo Vault? - but I've never seen that.
That's why I said that a deck who wants Transmute Artifact would need to be heavily leveraging what makes the card DIFFERENT from these other choices in a potentially positive way. Namely:
It costs UU. That's cheaper than Tinker and less Black than Demonic Tutor. So, maybe if you want a mono-blue artifact deck, this goes up in consideration. Traditionally the trade off of going mono color has not been seen as worth it by control players, though...
It's an Entomb for artifacts. In Vintage, the graveyard is halfway into play! This is the angle that seems to have the most promise to me, but it requires tons of (easily disrupted) things to go right in order to get an advantage. Plus, any deck who wants to use the graveyard has to ask whether they're better than Dredge, since they fall to the same hate.
I'd love to see some suggested builds using Transmute Artifact. Absent that, my suspicion is we're just not there yet. Here are the kind of cards that I think would push me to really want to use it:
Some kind of artifact fatty or with a powerful activation cost that comes out of the yard on its own power, like Metalwork Colossus, but with a more Vintage-friendly condition. Like, you can cast it from the yard by pitching other cards from the yard or based on storm count or I dunno.
Some other generally useful card that does something bah-roken if you have a significant artifact in the yard early in the game. Like, maybe a bolt where you can exile artifacts from the yard to do damage equal to their casting cost.
Something that rewards you heavily for being mono-blue and wants to be in an artifact deck. Like, Back to Basics that also makes your blue spells and artifacts cost 1 less.
I don't think any of these specific card ideas would be printed, but my point is that there are fissures between what Transmute does and what "better" tutors do that can be potentially leveraged by new printings.