Picard should have died in season 1 of PIC and the rest of the seasons should have concentrated on the new crew gallivanting across the galaxy in their newly christened ship, “The Picard”.
Cumberbatch should have been Gary Mitchell. He's got the right vibe for a man losing touch with his humanity as he's consumed by his godlike abilities, and a movie expanding on Mitchell would cover more new and interesting ground than plagiarizing Wrath of Khan.