homeassistant
Home Assistant is open source home automation that puts local control and privacy first. Powered by a worldwide community of tinkerers and DIY enthusiasts. Perfect to run on a Raspberry Pi or a local server. Available for free at home-assistant.io
Pi's are very hard to find these days. If you don't want to go full DIY assembly and service setup, then best bet would be a cheap android tablet, maybe rooted with LineageOS if you really don't want an assistant and no tracking, then just use the homeassistant app as a dashboard on it. You can buy a 90 degree power cable so that it isn't too noticable or even a flexible Qi charger adapter and put the charger hidden in a mounting bracket behind it.
I have a few leftover pis from other projects but its looking like a tablet will probably be the easiest/most elegant solution. I hadnt heard of lineagOS ill take a look into that thanks!
I bought a Fire Tablet HD 10 just for that purpose. It gets the job done
Newer iPads can run Siri offline,