That’s where the “don’t be there” and “don’t get hit” parts of self defense come into play.
I don’t need anyone in a forum telling me that I’m statistically smaller and weaker than roughly half the population (being female) and I can see with my own eyes that there is a significant percentage of the remaining half who are bigger and or stronger than I am. All that does is make me realize that I don’t want to go starting anything, and I sure want to be aware of what’s going on around me, because if my first realization is me getting hit or grabbed, I’m screwed!
However, a lot of times, the shock of the attack - punch, kick, grapple - is as incapacitating as the actual attack itself. If I can get to a place where I know it’s coming, or accept that I’m going to take damage, I’m already better off than the poor girl who’s frozen there with a shocked face because some skeezy drunk grabbed her arm or her purse.
As a complement to Krav Maga, I would also suggest Aikido, which is a great martial art focusing on deflection of momentum - basically using people and their appendages as fulcrums to make their own attacks break their joints or send them into the pavement.
Beautifully efficient and totally defensive (which is nice when you get to court later) - you only learn the attacks so that the ‘defender’ has something to defend against and practice on!
It’s also got some nice mental exercises about keeping your balance and stability so you’re harder to knock over, and some very fun and useful “disarming” moves, designed to remove knives, sword-length objects, and pole-length objects from people who are threatening you, and either dispatch them using their own weapon (which is fun in the dojo, but most likely illegal and immoral in reality), or dispose of it so that it isn’t a threat.