I don’t think there’s any real question that Meryl Streep is the finest actor of her generation. And at the risk of indulging in hyperbole, it might be safe to say at this point that she’s the finest actor of any generation.
Can you even conceive of a movie review that goes something like this: “The film is quite good but for the flat leading performance by Ms. Streep”? Of course not.
On the other hand, I’ve read plenty of reviews along these lines: “The film has its shortcomings but Ms. Streep’s commanding performance elevates the material.” Indeed, her very presence makes every film she’s in at least a little bit better.