Is 50% good? It's what you'd expect by posing "will AI do X by 2026?" and then flipping a coin to get an answer.
The coin-flip comparison doesn't really hold up. These weren't 16 independent questions with 50/50 odds. Some were safe bets, others were pretty far out there in 2016. Getting half right only tells you something if 50% was a reasonable baseline to begin with. Why would it be?
"By 2026, Google’s main product will not be search but AI."
You think this was a 50/50 coinflip statement in 2016?