It's not an either/or thing or even a particularly new decision point. I generally just ask myself for smaller projects if an OS is justified/worth it? If so,

It's not an either/or thing or even a particularly new decision point. I generally just ask myself for smaller projects if an OS is justified/worth it? If so, go with a SoC or larger running an OS. If not, go with a microcontroller. All that has really changed is the area of overlap between microcontrollers and SoCs continues to grow so it increasingly becomes a requirements/preference decision vs. only one or the other being possible.