For years -- nay, decades -- now, Intel has worked tirelessly to keep up with Moores Law, which states that the number of transitiors on a CPU die (and thus, its performance) roughly doubles every 18 months. First noted by Intel co-founder Gordon Moore, the observation has proved remarkably accurate for over 50 years, and forecasted the remarkable growth in computing power that launched the PC revolution first and the Internet revolution later, and is now responsible for the gigaflops and gigaflops of computation power sitting inside the smartphone in your pocket. However, in recent years it has become more and more difficult for Intel and others to keep up with the "Law." With each process shrink, the zillions of tiny transistors get smaller, the current they leak becomes larger, and the cost of the equipment becomes greater.
That's why in the last half-decade or so Intel has adopted a "tick-tock" model where instead of switching to a new fabrication process with each new generation (and thus absorbing the enormous capex and complex technical challenge of doing so), they're instead doing that only every other time, and spend the other cycle making more mundane changes under the hood of their last-gen CPU. For the most part, this has worked well for Intel. They get a new set of products to sell, their marketing folks stay employed thinking of reasons to compel consumers to upgrade, and the market gets last year's chips for cheap, since inventories must be cleared.
There's another beneficiary in this scenario, though: non-Intel CPU manufacturers. And these days, they mostly make ARM chips. While flagship CPUs from big vendors like Samsung benefit from huge R&D investments and process advancements, most manufacturers and most generations of CPUs are still several process nodes behind where Intel is today. So while ARM cores might be smaller and more efficient than Intel cores (or they might not be, it's very hard to get a solid answer on that subject), it's undeniable that they'd be more efficient if built on a more recent process.
While semiconductor fabrication technology doesn't quite follow the same "race to the bottom" curve as other tech manufacturing equipment, process improvements to trickle down a bit, and previously high-end manufacturing improvements are starting to show up in even midrange ARM chips now. To us, the OEMs, ODMs and end-users, that takes the form of better equipment at lower prices, even at low volume tiers. IoT hubs that struggled to manage a few devices are suddenly more capable, and SoCs that could barely throw a few graphics on a screen while managing a device are starting to handle more complex tasks in the same power (and heat) envelope.