They already are very popular. They're embedded in devices from smart home gadgets to washing machines and smart appliances.
The great thing I find about them is, that they are "hackable". Don't want to depend on some weird company and their cloud, especially with long-lasting appliances (which outlast the company cloud or even the whole company)? Just buy something with esp8266/esp32 inside, and there's a high chance, that there is some opensource firmware (tasmota, esphome,....) available.
(disclaimer: some times the "hacking" part involves soldering irons, wires, usb->serial adapters and knowledge of electronics safety, especially with mains powered devices)