Smart homes were more than just ideas 20 years ago, they were actually a reality, albeit a very different smart home from what we know and expect today.
To create a smart home back then, you needed to physically wire the entire house with multiple types of cables like ethernet, audio/video, and proprietary connections - it wasn't cheap (10K+) and wasn't simple (required professional installation), but it was possible. Even so, your capabilities were still limited simply because devices were designed to act like "silos" with no design strategy for interoperability or DIY (Do It Yourself) friendliness. So, there was no clear way to link a bunch of devices to create a complete home solution - but that wasn't due to the state of technology alone.
Actual technical challenges included the lack of broadband, wireless infrastructure, and no affordable and integrated GPS that could be used to detect your location on your way home from work and relative to your house - adjust the temperature, open your garage door, and turning on your front porch light at night.
Fast forward to now. Because people don’t have to re-wire their homes to create a connected ecosystem of devices, along with the new focus on simplicity and ease-of-use by brands and developers, the opportunities for new capabilities and integrations are endless. Devices like smartphones and tablets, and more importantly, the app store ecosystems, make installation and set-up seamless so anyone with a basic understanding of a wireless network could effectively design their own smart home. The costs have significantly come down as well!
And finally, a wider segment of the population is more sophisticated now and actually has an interest in having smart homes. As a result of the value proposition it brings, most homes now have wireless networks in addition to their broadband. This creates reliable networks that incentivize people to search for additional products to add to those networks, like Wi-Fi TVs, Amazon Echo, and wireless thermostats - not just the traditional computer which was what the original Wi-Fi networks were specifically designed for.
So really, the IoT is not just a matter of advanced and readily available technology, but also proper timing and a totally different consumer mindset. All of these factors have converged so that now the time is right for wide mass consumer adoption.