The reason Magic is such a great game is because no matter what powerful strategy a player comes up with, there is always a way to beat them if you have the right tools and a little luck. This balance can persist because each of the five colors has a very specific profile of strengths and weaknesses.
Another reason that using (and thinking about) the cards is so much fun is that the characteristics they share are familiar: they make sense in terms of the metaphors that resonate with the real world (and the lore of certain fantasy traditions).
A big part of the game is guessing what your opponent might do based on which colors they have at their disposal. Each color has techniques it does all the time and actions it can never do. The best example is how each color does creature removal. Black can destroy creatures, sending them to the graveyard. White can often exile them, so they are out of the game entirely, especially when they are attacking or blocking. Blue can tap them, steal them, and return them to your hand. Green can kill your creatures through fighting if it has bigger ones. Red can kill them if it can do damage to equal or exceed their toughness.
Creature removal is an important aspect of the game - but the color pie has dozens of elements. Blue can counter (cancel) spells, black can make the opponent discard, red can borrow creatures, green creatures frequently produce mana, and white can prevent damage. When colors combine on a card, they might get to do anything that either color has access to.