Like must meet like. If you strike back with physical abuse against verbal abuse, you are escalating the situation unilaterally. Your duty is to deescalate, not escalate, the situation.
Verbal abuse must be taken seriously. So too must all forms of emotional abuse: Gaslighting, fostering codependence, etc. But verbal abuse has important characteristics that make it unlike physical abuse. It is not coercive: One can leave, or put on headphones, or yell back. Of course, in practice, everything from monetary issues to social problems to the presence of children can make doing that much more difficult. But there are still options that are just not present at the time of physical abuse, which is by its very nature coercive. And while physical abuse is relatively unambiguous, both partners often feel like they are being treated capriciously or abusively. This ambiguity and the different memories and experiences both partners have makes it very difficult to justify acting against perceived verbal abuse even with matching verbal abuse, let alone physical abuse.