What you're describing is the same for every having algorithm in existence. All hashes can represent multiple (indeed, infinite) passwords. So they all have col

What you're describing is the same for every having algorithm in existence. All hashes can represent multiple (indeed, infinite) passwords. So they all have collisions. This is because all hashes are fixed-length, and so finite, while the possible inputs are infinite. This isn't the reason that MD5 is weaker than other algorithms.