Dwayne 'the Rock' Johnson (Reuters/Lucy Nicholson)

Apple wants everyone to like Siri. Everyone — it seems — likes Dwayne “the Rock” Johnson. Therefore, it makes sense to show the Rock liking Siri.

That at least seems to be the logic of a new commercial from Apple, featuring Johnson — Hollywood's highest-paid actor and (seriously) possible future presidential candidate.

Getting people to like Siri is critical to Apple now, not only because it faces an increasingly crowded market for vocal assistants — as everyone from Google to Samsung tries to create software that lets you talk to your gadgets to get things done. And the company is counting on Siri to power its own home vocal assistant, the HomePod speaker, that's due in December.

While Apple was the first major smartphone-maker to put a voice assistant in its devices, it has faced struggles in the past few years and no longer holds an uncontested position at the top.

Sure, Apple still holds a lead over its competitors in terms of how many people use Siri — 41.4 million for Siri, the report said, to Amazon.com's 2.6 million and Microsoft's 700,000 —  according a recent study from Verto Analytics. (Amazon chief executive Jeffrey P. Bezos owns The Washington Post.)

But Siri engagement has dropped about 15 percent over the past year, TechCrunch reported, meaning people are not using it as much as they once did. Engagement on other assistants, including Microsoft's Cortana and Amazon's Alexa have meanwhile seen their engagement more than triple.

That slumping engagement could explain why, in an extended ad released Sunday, Apple highlights the frenetic pace at which Siri can keep you informed and focused on your goals.

The ad may seem a bit of a letdown after some speculated Apple would tap Johnson for a movie to further Apple's own push for original content, but nevertheless, in a 3:45 spot, Johnson and his compatriots consult Siri at least 11 times.

Apple also plays up an advantage that Siri holds over, for example, Alexa: its mobility. While Apple is on the cusp of releasing a stationary speaker itself, it still makes sense to highlight that Siri is also available on the go and integrated into the phone. That hands-free, voice-activated ability comes in handy in the commercial when, for example, Johnson is doing some light touch-ups on a Sistine Chapel-like ceiling in Rome after redirecting an Akron, Ohio-bound plane to the Eternal City.

Johnson also uses Siri in the ad to set reminders, create to-do lists, read email and call a Lyft. He does not use Siri or Apple Maps for navigation, which is somewhat hilarious given Apple's past problems competing with Google Maps. One can only assume that calm, orderly navigation wasn't as exciting as the stunt driving sequence that did make it into the spot.

The ad is, however, mostly an ad for the Rock, as CNET's  points out. The parts of it that are cool are about the Rock being cool.

Because, really, what would make Siri more useful is not what you can make splashy ads about. That includes, for example, better understanding of basic human speech, and more features that are truly useful — things you need even if you never politely hijack a plane to go to Italy. Siri's been steadily improving, but the thing that turns people off of using it is that it doesn't work consistently enough to do the things they want it to do.

Case in point: Just for kicks, I asked Siri for the temperature in Rome after watching the ad. My iPhone replied, “I'm sorry, that feature isn't supported right now.”

Puzzled, I looked down at my phone screen.

“What's the temperature in Room?” the transcript said.

I Googled it instead.