By playing this card early in the game you have the opportunity to slam your creatures without fearing your opponent playing board wipes
Gwenom, Remorseless Want to play a Bolas' Citadel that isn't a game changer
Because you have 40 life, Griselbrand is capable of drawing a ton of cards and winning the game on the spot
You can either build this to use mana generating spells and then finish off opponents with something like Grapeshot, or you can just have fun by pew pewing everyone down
Filigree Familiar looks primarily like a creature to sacrifice to Elder Deep-Fiend, Wretched Gryff, or Distended Mindbender, but I could also imagine people wanting a speed bump early or just wanting an extra artifact for some kind of artifact synergies
Nobody ever gets it right on the first try, and some players may take months or even years for their deck to be just how they want it