Director's Final Films

I think that was because the top three vote-getters are all better films than it.

Tbf it’s been a while since I’ve seen Imitation of Life, so maybe it’s time for a rewatch.

Of the eighteen I've seen, I'd have voted for The Sacrifice. My notes indicate that I saw The Ascent in the theatre, and I have absolutely no memory of it. Weakest is probably Lola Montes, a big fancy cake that spins and spins in front of the camera.
I have a pet theory that if Tarkovsky had lived to make another film, it might well have been terrible. He was keeping such a careful balance of mysticism and absurdity, and I can't imagine him pushing forward from this film without that equilibrium collapsing. But who knows whether it would have been made back in the USSR or in the West, and how that might have affected the production and the reception of it.
Most notable final film that's not on the list is The Turin Horse, which I regard less as a movie than a preview of dying.

That Tarr is still alive just underlines that.