It's trivially easy to get it into your graveyard: that puts an Artifact into the graveyard, handy for turning on a Dragon Rage Channeller's Delirium ability or pumping up a 'Goyf, and providing another card
It's important to keep cards that will help you add gas to your tank, so try to hold onto cards like Lucky, Pongo, Tinker Bell, Strike a Good Match, Hypnotize, and Improvize when you see them
The original Dominaria had 97 historic cards to untap it
The longer and more technical answer is that Hiram had phenomenal, borderline broken, synergy with Pawpsicle and Fortisphere , two inexpensive item cards that cost just 1 ink each and also allow you to draw a card when they're played
, : Creatures you control gain flying and lifelink until end of turn