2016 will be remembered as the year of close-to-the-metal graphics APIs. I doubt your grandma will bring it up in conversation as you discuss the highlights of the year come Christmas, but you know, you can always try. If she wants examples, no worries granny, you'll be able to fire up Dota 2 because it'll be Vulkan-enabled by the end of the week.
That's the plan anyway, according to Valve's Fletcher Dunn, who posted the following comment on Dota 2's sub-reddit:
We're going to release vulkan support soon, probably sometime next week. That DLC checkbox is an error and shouldn't be visible yet. Sorry for the confusion.
Vulkan support arriving before DirectX 12 is in line with Valve's comments last year that suggested Vulkan's cross-platform nature would make implementing the latter, Windows-bound API a lower priority.
If you needed further proof Dota 2's Vulkan support is imminent, all you have to do is hit up SteamDB, which shows the latest update adding depots for "Dota 2 Vulkan Win64" and "Dota 2 Vulkan Linux64". Great, unless you're playing on OS X.
Much like glass coffins, whether Vulkan provides a significant performance boost remains to be seen, with Valve itself admitting that Dota 2 isn't the "ideal candidate" to show off the API's benefits.
Still, I can't think of a better way for the company to battle-test its implementation than whacking it into the most-played game on Steam.