I liked the wonderful Wilby Wonderful even more than you did, I suspect, as I found the movie quite moving. And delicate, actually. I suspect some of the mediocre-review-writers have mistaken subtlety for inactivity.

One of MacIvor’s great talents is writing characters who make their biggest changes, and dramatically important ones, between their lines. This forces / allows the actor to think the change, as opposed to speaking a line telling the audience they’ve changed, and as a result the characters convey a greater complexity. Words are sledgehammers compared to a slow narrative flowing through an actor’s features.

To the patient and observant goes the greater prize.