AMD unwraps Ryzen AI 300 series "Strix Point" processors - 50 TOPS of AI performance, Zen 5c density cores come to Ryzen 9 for the first time | Tom's Hardware
It's been existing for many years now. Just think of all the image processing going on when you take a picture with your smartphone for example. NPUs have been in smartphones for years (I think Apple had their first NPU in the A11 of the iPhone 8 in like 2017).
Manufacturers simply didn't call it AI back then, and now it's a buzzword. And these "AI" features are getting more and more complex, so notebook chips now need dedicated NPUs to run this stuff quick and efficiently.
With smartphones being "good enough" (even in the mid-range), they really need AI-focused marketing to try and push upgrades. Same with PCs and laptops.