The scenery-eating pestilence that is Kate McKinnon absolutely ruined “Yesterday” (2019). That’s too bad, because the premise of a struggling busker suddenly waking up in a world where seemingly only he knows the works of The Beatles is brilliant. The “Masquerade” plot structure is deployed skillfully as the busker struggles to have his false voice heard, then rockets to stardom. The climax is clever and the story amazingly finds additional poignant twists as it parachutes to its conclusion. Except someone thought McKinnon would provide (unneeded) comic relief as a record exec. Her character’s existence is an unwanted irony unto itself.