For one, it’s a boolean value, and can be saved as such requiring only 1 byte of storage space. If you save it as a string, you will require at the very least 3 bytes (for “No”) or 4 bytes (for “Yes”).
That’s not to mention that you have little control over what the value actually is. Another part of the code could, by mistake (or even on purpose), save “Bob” as a value, and your code would then fail to work. Unless you wrote in safeguards against that, in which case the added complexity would pretty much negate the purpose of doing it this way.
Also, It doesn’t really make any of this any simpler, just very slightly different.