In terms of direct impact on the game, Mishra's Bauble might as well not exist - and if you want to increase the consistency of your draws, that's perfect
White creatures usually have lots of keyword abilities like flying, first strike, double strike, lifelink, or vigilance, and as such it makes sense to enhance those
If your commander has only colorless mana symbols, such as Karn, Silver Golem or Ulamog, the Ceaseless Hunger, you can only use lands that produce colorless mana
The former can come in as copies of Cosima, and, if theyre around on your upkeep, can be sent away using her trigger
Your card cases should provide the best possible protection for your cards, with the material being secondary