But a simple thing like "install a random cli tool to run on host" is often not easy on immutable distros, so it's usually just more convinient with an oldschool distro in those cases.
To be honest. Immutable distros are not for everyone.
Tinkerers especially would not be suited to use them, because of all the "restrictions" in place.
You don't have to use all the features. Restarting a service is a pretty broad feature.
If it's too broad, You will likely have to code something yourself.
If you don't have another server, this is likely your best option.
It's a simple app, that pings the website on a given interval and gives an app notification if it can't reach it.
In my area we have a brand called LEDvance, which ships both wifi and zigbee bulbs. I have some of the Zigbee ones and I don't need anything other than HomeAssistant to add them to my network.
This is the way to do it.
Although, I can't get it to do facial recognision on my external library for some reason.