The Black Widow movie was... okay. On a par with recent Bond movies, No Time To Die aside (and no decent villains in any of 'em, dammit.)
And Flo Pugh kind of knocked everyone else offscreen.
But it didn't bring closure to Nat's story, or the pain that losing someone you're close to leaves behind - explored gently in Ep4.
Also, we may not have to get closure: another Nat (alter-Nat?) might take her place, as in the What If? series.