Booleans should be just True and false
Accidental complexity coupled to one particular language.
Difficulty to hop among languages.
Work with booleans for boolean conditions. Not integers, not nulls, not strings, not lists. just booleans.
This is a language feature. Some strict languages show warnings with this magic wizardry.
Some languages encourage doing some magic abbreviations and automatic castings. This is a source of errors and a Premature Optimization warning.
We should always be as explicit as possible.