A lot of these decks will be playing super equivalent small guys, attacking and blocking will often mean setting your board back to 1 or maybe 0
Not for what it does, just in general
Drawing two more cards, even if you have to cash in a token to do it, is one of the best things you can do in that scenario
5 Podding Keep Climbing Upwards Born from a green artifact printed back in 2011s New Phyrexia, Birthing Pod, this style of card is a popular way to upgrade your creatures turn after turn until you get one big enough to win the game or you snag some combo piece
Those in-game purchases mostly involve unique in-game currency, which is then used to purchase card packs and entry into special sealed formats
WotCs own ban announcement called it quite simply, too strong for the format