Kind of like saying that “cell” and “sell” are different words. Obviously they’re different words, even though you can’t hear the difference. Just like it’s obvious that Ab and G# are different notes, even though they may sound the same.
Ask an English speaker to interpret a text about a sails man who sales around the world and cells sell phones, at have price for any guessed who sends him a facts to his office in grease.
It’s harder to read when you use the wrong words, just like how a score is harder to read if you use the wrong notes.