Your pattern is more and more the exception and not the rule.
And I hope to be that exception always. I have a cell phone essentially because I sometimes need to make a call when away from home but there are no longer any phone booths. And, it represents a level of security in case I ever need to call 911.
So, since I am forced to have a cell phone, I do it as cheaply as possible....buy an inexpensive phone and keep it until forced to replace it (as inexpensively as possible). My monthly plan costs only $11.20. I have a landline phone as part of my low-cost internet package (my ISP is a telco) but don't have the level of crank calls that you get. In fact, it's now none because the telco provides a blocking service that is easy to use.
We are in our seventh and hopefully last home which is wired for everything so I'm not too worried about new home developments. Maybe my epitaph will be: "We wanted to warn him about the danger but couldn't get in touch."
My kids are not different than yours (cellphones only) but I must admit....every time I hear them say how much they're spending on a new phone, I cringe.
