Shameless plug for Home Assistant, here. Everything is controlled locally (unless you pay for their internet pass through service which is basically just a relay), most brands of smart devices are supported, you have extreme customization capabilities, and it's all open source.
Shameless plug for just using your little fingies to operate the light switches and thermostats. Everything is controlled locally and you only have to pay for the light and the switch (fingers should be included in your default setup)
Fingers may be included in most setups, along with actuators like arms or legs often required to approach the finger to the switch, but they still come with a wetware control unit that gets easily distracted by anything from puppies, to the fear of being late for work.
That's a good point; generally my little fingies aren't the problem as much as the control unit.
Honestly I'm just a bit of a luddite when it comes to "smart" tech, which I guess is somewhat funny considering I've worked in IT for a looong time. Or maybe it's because I've worked in IT that I turned into a luddite?
I've been so deep for so long into the "DIY IoT", that now I look like an IoT luddite. Funny how that works.
For example, I've had the idea of a bistable electro-mechanical light switch on the back burner for so long, that by the time I've found a practical solution, decades had passed and it was burned to a crisp, with other stuff having taken center stage.
The idea was: a normal light switch, you can turn it on or off with your finger, and it will stay that way, even if power goes off. A remotely controllable switch, the easiest version would be a relay, that stays on as long as it is powered, and goes off otherwise. I wanted something that would be remotely controllable, but would stay in the last position no matter whether power happened to go off or not, and wouldn't use power to stay on. There were bistable relays like that, with two coils and permanent magnets: energize one coil, it switches that way; energize the other, it switches that other way; with no power, it stays in the last position, just like if you had flipped it with a finger. Only... those bistable relays were bulky, expensive, and you couldn't flip them with a finger. I wanted both things: flip with a finger and stay, and flip with a signal and stay.
Nowadays there are some switches that have a sort of bistable relay built in, a couple coils that switch it on or off depending on which one gets energized, and it stays that way... but in the meantime the whole idea kind of became obsolete. Now you get SSRs that use negligible amounts of power for a very long life time (no moving parts), and dirt cheap microcontrollers with also negligible power draw, that come with enough memory to store the last switch position along a firmware to connect wirelesly.
The "purist" in me would still want a bistable electro-mechanical switch, but the practical side tells me "who cares".
Now my pet peeve is that those smart switches, don't all come with all sorts of sensors, which are also dirt cheap nowadays.
Personally what I enjoy about hobby projects – and I'm just blithely assuming this is one – is that I can be just as much a purist as I want. Sure, it's often impractical and ends up taking much more time than a straightforward solution would, but if I'm doing it just for me I'd rather make something "beautiful" (for some very subjective definition of the word) than useful. I'll probably enjoy the process more, and for me the process is at least as important as the end result.
They aren't mutually exclusive, I have a few smart lights and I try to plug them into switched outlets so I can turn them off manually and also control digitally.
Controller locally except that one case - also unless you add devices that are cloud controlled (most things that say they are Alexa-compatible, most Wifi things, etc). Which a lot of people may not realize, and it's a LOT of things). But is totally up to people to use, and there's often a way to make (or hack) those things to be local-only.
Home Assistant really is best-in-class though for most Home Automation things. It's super super powerful and supports virtually EVERYTHING, especially if you can put in a little work. And for medium/advanced users, it's peerless.
They just still have a really long way to go to be as user-friendly as it should be. Even for "advanced" users.