Despite how long defender has been around, there aren't a ton of cards with defender in the game compared to other mechanics of its age, largely due to the pool of defenders being kept purposefully small as, by their nature, they have much less use than other mechanics outside of Limited formats
Learning how to tame spontaneous ideas into relevant decks is an effective skill to have as a deck builder
Doubling Season sees competitive metagame play in 1 format(s): Commander
But you can still tap any of your summon-sick creatures either as part of the cost or as part of the effect of another card, like a convoke or improvise card
Having it for artifacts pushes this one to the top, as it is one of the easiest restrictions to fill
It wasnt just the artwork that surprised me - I love the improvements and differences the newer cards have compared to the original Wizards of the Coast-era products I collected growing up