Apple has face recognition. You steal the phone, you better steal the face of the owner too.
There are apps to break the password, but if you create your password the right way, it can take thousands of years for a computer to hack it.
For example: A 12-character password containing at least one upper case letter, one symbol and one number would take 34,000 years for a computer to crack.
This Chart Shows How Long It Would Take a Computer to Hack Your Exact Password - Articles - Automation Alley.
I use very long passwords with multiple special characters. Also with apple, apple will suggest a long password with multiple special characters and 2 factor authentication.