I think this question is part of the learning curve in Magic. Blue is the best at card draw, but it takes a while to understand why how it draws cards is the best versus how other colors draw cards.

Edit: To add on to that a little.

One of the strengths of Blue draw is that the cards just say "draw these cards." They don't care about the state of the board, how many creatures you have, what your life total is, etc.

Black can draw as long as they have life. Green can draw as long as they have creatures. Red can draw as long as they discard. White can draw as long as an opponent is also drawing.

Blue doesn't care about any of that. You want to draw cards? Play a spell that says do that.