There's a reason that spark plug technology has not changed in 150 years: it works. The mechanism of a spark plug (and many mechanisms inside of an internal combustion engine) are so simple that they leave little room for mechanical failure.
Everyone likes to make the joke about "If Microsoft built cars", but there is some amount of truth to it - automobile engineers value simplicity far more than computer programmers do, as it has a direct effect on reliability. The reliability of a car is far more important than the reliability of an online chat application.
Spark plugs as they are now solve the problem, and are cheap. You can buy one for about $5 where I live. That one plug will last years. If by chance it does get dirty and start to fail, I can pull it out and clean it with a wire brush.
The "fuel efficiency gain" from a laser plug needs to be substantial to justify the complexity and expense. Leave it to journalists to ignore the practical side of a story and make it all 'science'.