It was a strong piece in the kicker archetype in that Standard format, buying back a kicker card from your graveyard
The payoff is that ninjutsu allows us to reset our ETB creatures, which is precisely what we want
Goldvein also has Vigilance, Trample, and Haste, making it a scary card to see played, especially when the X cost is so easily raised by the Commander
Its not the best thing you can do in Hearthhull, but any excuse to sleeve up a Reserved List card is enough to send that cards price rocketing to space
Not every mechanic needs to herald a huge evolution in how Magic is designed and played, but the sheer potential of Treasure to improve the average game experience has me wishing it becomes evergreen
Now, I do think that last year's Core Set 2019 was not pushed much at all, as it felt very by-the-numbers to me in places