Consider taking this a step further and trying no phone at all. But instead of doing something extreme like dumping your smartphone, just turn your current phone off unless you're OK with being reached and at home or at work. Anything in between, the phone stays off.
This makes your smartphone a de facto land line for all practical intents, and you get to keep the potential to make exceptions and use it for e.g. GPS and maps or a restaurant lookup when you need to.
Another possibility to consider is carrying a pager. That way you'll at least know when you've got a call or a voice mail, and then you can turn your phone on temporarily to call back or check your voice mail, instead of having to periodically turn on your phone to check for missed calls.
Actually, the whole point here is to not be reachable unless you're OK with it. If you're working as e.g. an emergency doctor or a firefighter, or you're responsible for keeping Gmail/Google Drive up, it's a different story of course. But most of us aren't dealing with urgent -- as in life or death, or impacting gazillions of users -- situations that can't wait an hour or two.
Then you can also just go into Airplane mode. But that takes discipline.
Much more liberating is, to have a smartphone where you can put out the batterie ... then it is off. And since putting it back together takes time, the temptation to just check something is way less.
I just wish there was a better middle ground. iOS's DND is great in letting me whitelist contacts who can punch through, but that only applies to calls and texts, not signal :/
This makes your smartphone a de facto land line for all practical intents, and you get to keep the potential to make exceptions and use it for e.g. GPS and maps or a restaurant lookup when you need to.