mtg cards new set Magic The Gathering Streets of Capenna Bundle Exile Soul of New Phyrexia from your graveyard Teenage Mutant Ninja Turtles Magic:

On the other hand, Birds of Paradise costs the same one green, has flying, and can tap for any colour

Being able to produce one mana of any color allows for a more varied deck, without having to put in a bunch of lands to power a couple of cards

This is how a reback looks after the bend test:

The only format where it sees any play whatsoever is Modern, where it is at best fringe, and the only reason that Goyf carries a price point anywhere above dollar rare status is ingrained price memory

Some Universe Beyond precons falter because they focus more on printing new cards than building a cohesive strategy, as seen here

Finally, a "continuous" artifact has a static ability, but that ability would turn off if the artifact became tapped