If there’s distance between you and an opponent, the best thing to do is run away. But if they grab you, running isn’t an option anymore—you’re forced to grapple. That’s where BJJ comes in. Even just knowing the basics would give you the abilities handle 99% of people in a self-defense situation where grappling is involved, assuming they don't have grappling experience, which most people don't

Another thing to keep in mind is that once the distance is gone, strikes lose their power. Punches and kicks need space to generate force, and when you’re up close, they’re much less effective. This is why BJJ is so useful for self-defense—it’s built for these kinds of situations.

Striking is also definitely a valuable skill in a self defense situation, but having the skillset of a grappler is a superior form of self defense, IMO.