I think the key would be to embed it to some existing appliance; like a router, game console, or other "always-on" and connected device.

I don't see the home server being the prime selling point. Everyone needs a router, so if you created a router that was dead simple to configure and use, had some cool extra features, integrated well with your home gadgets ("Alexa, turn off the WiFi", "Alexa, setup a guest wifi network for the next 8 hours") and on top of this acted like a home server, people would buy it.

At least from a consumer product perspective.