The low-cost activated ability makes drawing cards inexpensive and the triggered ability upon 8+ stationing is a passive and casual win condition with the land sacrificing engines Hearthhull promotes
By turn five you will have gotten her to scry 2 twice, and five loyalty, before anyone else is bothering to swing, and then you can drop any land or creatures with a cost of five or less onto the battlefield for free starting on turn five, and every turn from then out
Imagine a world where Magic cards are just blank with a QR code
Adaptive Automaton Sleeve from the October 2022 Superdrop Secret Lair
Compare that to Base Set, where the most powerful attackers werent ever 1HKO-ing each other, and many struggled to even 2HKO, which made games significantly slower to the point where deck-out was a common win-condition
The new format doesnt have a lot of permission, and is lacking Noble Hierarch (thankfully) so a three-mana walker is looking pretty good, especially when it comes down on turn two and bumps to six loyalty immediately