When NUCs appeared they were the only player in that field; now if you search for "mini pc" at any vendor you're submerged by the amount of products, of which NUCs are only a small and more expensive fraction. Intel can't compete anymore with other manufacturers and abandoned the market, but the form factor is stronger than ever and demand may only rise in the future with faster and less power hungry CPUs. For office usage, and generally where is no need for adding PCIe cards or very high speeds (read: heat dissipation), they're already dominant in many places: I was just back from a real estate agents office in which all PCs in sight were Lenovo mini PCs fixed on the back of their monitors, the supermarkets I shop from all use mini PCs by other brands, as does my bank and a lot of other stores and businesses I visit. My own media player is a unlocked Chromebox reflashed with LibreElec. One should rather wonder how much until Mini PCs can also mount very high end GPUs so that they can be adopted by the gaming community and other niches where speed is a must.