Cards like Casa Madrigal provide lore generation, while characters like Bruno offer revival abilities
Those are just a couple of the considerations, but Mark Rosewater has an excellent article on DailyMTG that goes really in depth about the design process for our Universes Beyond video game properties, specifically: There are a lot of video game franchises that are a bit more adjacent to the usual fantasy-style of Magic: The Gathering - what made Fallout such an attractive choice for an early start on these crossovers
Plus, those animated permanents draw you cards when they connect in combat, turning utility pieces into threats that stick around
There are several uses for colourless mana in green ramp too and Signets fail to help there too
Being able to explore your likes/dislikes and comforts/discomforts is what makes a playgroup or meta healthy
I know Ive made my love for Trinket Mage clear before, but it can have a huge impact on any deck that runs it