QuoteAlbacore showed, you can enable the feature on processors that don't meet the 40 TOPS requirement.
... Of course ... not as smooth.... As you can guess, it's mainly because the ... processor doesn't have a powerful NPU to process the snapshots taken by the Windows 11 AI feature.
That exactly. That is the real reason why they introduced the NPU in processors: so the NPU can do that task (making screenshots every 5 seconds) in the background without interfering or slowing down other programs. That's the main reason.
Everything else (like using the NPU for AI related tasks on pictures, music, videos, gaming) is mostly an excuse. Although it theoretically can be used for that as well, it would also work with a simple AI software library, which uses the CPU or GPU for the calculations. There was never a need for NPUs on average PCs or for the average Joe. At least not for the next 5 years. For the few people who really need an NPU, extension cards could have been made.