Isn’t scratching a car stealing the resale value? The owner has to pay to get it fixed to restore the value. Therefore, vandalism is theft. Quod erat up your demonstrandum :)

Also, assault is theft (of peace of mind), rape is theft (of trust), flaying someone alive is theft (of skin).

If you want to stretch the definition of theft to include any harm, even without depriving someone of their property (i.e. the actual definition), you make the word meaningless. There are already words for other crimes.