If Moses killed the Canaanite tribes, why are so many Jews part Canaanite?

I’m half Jewish, discovered I have some ancient Canaanite ancestry (look at my post history), and I’m genuinely curious about this because I can’t find answers online. I’m asking this in good faith.

Admittedly I haven’t studied Torah. But I was reading parts of it for the first time recently, and it looks like Moses conquered all the Canaanite tribes and ordered them to be killed (yikes 😕).

However, Ashkenazi Jews seem to be around ~35-40% Canaanite, and Mizrahi Jews can be as much as ~65-70% and above. Why??

I’m mostly wondering why a people would create a founding story about… themselves being killed? 🤔

Can someone please explain this?