question about curing – “sushi guy ” video


complete beginner to sashimi prep so please give any details even if they seem obvious

I was watching this video by sushi guy: https://www.youtube.com/watch?v=br0x70CLoz0 (title: Sushi Guy's Guide: Trader Joe's Salmon for Sushi Use)

since i plan to buy the same salmon at my local trader joes

I'm wondering if and why the curing is necessary?

can I not just eat it directly after slicing it from the package?

by Potential_Simple9057