It's not intended to fix anything permanently. If a person can read the
label on the can they will be aware of that fact.
It will not fix rim leaks or larger leaks. The major advantage is that
it will put a bit of air in a flat tire and perhaps enable a person to
get to a repair station. It's easy to use and a non-technical person
can use it.
On the downside it throws the tire off balance, can be flammable, and
is very messy when the tire is finally fixed.
A better idea for the person who can do so is to carry one of those
little 12V compressors to blow their tire up in an emergency. A further
step would be to learn how to plug a flat tire from the outside with a
kit.