ALL alphabets lack symmetry because they are composed of many different letters.

There is so many different alphabets because there is so many different languages. Every language has a different alphabet. Even the English alphabet and the Spanish alphabet are different, even though not by much.

There is no exact count, because it's hard to define what a fundamental difference is between alphabets, but a rough estimate is in the neighborhood of 100 natural alphabets, and thousands of constructed ones.

There are many alphabets used in Canada, but officially there are only 2: the English and French Alphabets.

Every distinct alphabet on the planet is different from all other alphabets.