Mono-Blue Commander decks are renowned for drawing lots of cards, protecting combos, milling libraries, cheating in Artifacts, and somehow still having the audacity to say they're just a casual mono-color deck
It can grind extremely well with cards like Expressive Iteration of Lurrus the Dream-Den, while still being extremely efficient
It happens now and again and is a big perk but you don't need it for the card to be good
Play your favorite moments of the Third Age or turn Middle-earth on its head and surrender to the temptation of the One Ring
Or, you know, turn a green mana into 3 of another color entirely
In the previous article ranking the top blue cards in Modern, I talked about how the big difference between Modern and Legacy historically has been the lack of universal answers in the former, while the latter has cards like Daze, Force of Will and Wasteland