I have nothing automated in my life, that I know of? I don't have a garage; the door to the house has a key; the lights I turn on with a switch; no Alexa, don't use Siri... I am not exactly opposed to automation, but I am hesitant to share even more demographic data to cloud services.
Problem is, it comes with a ton of headaches.
The cloud is a problem, as you noted, but also a bunch of fiddily, unreliable software, firmware updates that go haywire, and apps that are tied to iOS and will stop working with my physically installed home hardware if the manufacturer ever stops treading water and fails to update for the latest breaking iOS update.
Home automation could be simple, reliable, and future-proof. It’s really not, though.
Everyone is chasing the lowest price, and it has to compete with existing solutions that are cheap, like just putting a filter on a white bulb, or installing a dimmer switch. What these products are offering is convenience, but not fundamentally new life experiences. So they can't charge a lot.
Meanwhile, they have to interact with an absolutely enourmous range of interfaces. The wi-fi router, the phone, the electric service itself, etc. And the user has high expectations for ease of use (after all, it is a light bulb, it should be simple!) while needing good security (it is your home after all, if you can't be safe in your home then where can you be safe?)
A simple experience with a wide range of interfaces at low cost has almost never been successfully done. Even Apple can't do it; they offer ease of use, but in a limited ecosystem and at a premium price.
So these products are fundamentally flawed and they probably can never be fixed. This industry is fundamentally not viable until someone comes along and solves the interface issue or until people accept paying a lot of money for these kinds of things, and even in that case it would probably be a reseller performing a home install then providing API access to these services, which is only one step away from home-as-a-service.
And I personally do not think I could tolerate a home-as-a-service. But many young people or students might like that just fine.
Depending on your definition of future it's very possible. Find some devices classified as "Local Push" or "Local Polling" https://www.home-assistant.io/blog/2016/02/12/classifying-th.... Make a VLAN with no internet access in your router and put them (and HA) on it. Never update the firmware (why would you, they work don't they?), connect them to HA and pin the version of it and your plug-ins. Don't let the devices talk directly to HA if you're extra paranoid.
Update at your leisure or never.
Their model is shipping ESP devices flashed with open source firmwares. They still go on their own firewalled wifi network, but this is about as future-proof as I can imagine: the software is open source, the updates can be run locally, the parts they're made of are actually pretty simple PCBs you could get a fab run of your own done if you wanted to.
In terms of "future" proofing, everything I've installed I've been putting in accessible junction boxes well labelled - electricity isn't going to change, so as long as it fits in a box, I'll always have the option to replace the hardware (if you have light switches with a neutral wire then you're basically set).
I wouldn't say "simple" per se but that's really more on the "you need a box running some type of home automation stuff". I suspect simple enough for the consumer would be something which came with it's own wifi AP and pre-configured mesh routers so the IoT network would start out intrinsically separated.