The thing is, theyre not great at actually doing damage
The simple and clean design helps this card stand out as a great representation of the Metal type in the TCG and is a cool vanity addition to any modern deck
Some commanders work well with huge, trampling creatures, others with vast armies of tiny minions, and some with as few creatures as possible
At that point, spending give mana just for a few tokens and lifegain every other turn seems like a bit of a waste
I particularly like Wall of Roots, since you can use up all of your mana on your turn and still have access to one green mana on each opponents turn in case you want to cast a one-mana instant spell
For all intents and purposes, it is the chosen card for the turn no matter what happens to it