The reason Battlemage's Braces is on this list over Illusionist's Bracers, which does the same thing, is colourless, and is free, is because Battlemage's Braces gives your creature haste
1/1 Illustrated by John Di Giovanni Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Not Legal Modern Not Legal Brawl Not Legal Legacy Legal Comp
Youre more likely to pull something exciting from any given box
Some decks can get behind spending 3 mana and an artifact to double a creatures power, and theres plenty of value in an equipment that replaces itself and brings two artifacts into play
In the rare case where a legendary creature becomes a copy of another legendary creature with greater mana value (for example, if Sakashima the Impostor is a copy of a legendary creature with mana value 5 or greater), then when that creature dies, if it's still a legendary creature card in your graveyard, Havi's last ability will be able to target it