[Yen]

Firstly, research into Chess AI has had a surprising amount of beneficial spin-off, even if we don't call the result "AI".

Secondly, while it's still a simplification and abstraction, DotA's ruleset is orders-of-magnitude more similar to operating in the real world than Chess's is.

Thirdly, I'd argue that the adversarial nature of games makes it _easier_ to track progress, and to ensure that measure of progress is honest.

There's a lot of ways you can define "progress" in self-driving cars. Passengers killed per year in self-driving vs. human-driven cars? Passengers killed per passenger-mile? Average travel time per passenger-mile in a city? etc.

With games, you either win, or you don't.

[jjcm]

Another benefit of showing off progress with games is it allows the everyday reader to follow and understand it as well. It works great as a public awareness standpoint, especially when an AI can beat a human (i.e. Gary Kasparov vs Deep Blue). Awareness is a good thing in the space.