When I was young, I used to have this with a friend who lived next door. It was amazing to have a free, private, always on hotline. If memory serves me right, it even worked for playing Starcraft over 56K baud modems!
You would likely have connected closer to 33.6k. 56k modems can only receive at that speed, to send at that speed, you generally need a digital line like a T1 or maybe ISDN.
For ringing apparently you need 60-100V AC, I'm not sure what a simple solution for that would look like. https://en.wikipedia.org/wiki/Ringing_(telephony)
How to our landline: Go to my wife's desk. Pick it up. Dial 911. He literally has to say or do nothing else as the address is registered to the phone by virtue of being a landline and if you say nothing they send people. (We did tell him to talk to the person, but I just mean even if he's not understandable or too scared or worried to talk things will/should "fail safe". (We also made labels for the back of the phone with a big 911 on it, along with some smaller labels with alternate contacts for when he's older or if we have a babysitter over.)
Our cellphones: find the phone (which sometimes takes us forever under better circumstances). Find the power button. Hit the power button. Find the little phone icon. Drag it up just right without letting it "drop". Dial 911. Give the operator our address. Now, if he's too scared, worried, or freaked out to talk or be dextrous enough to handle a touchscreen or remember what to look for to bring the emergency dialer up, &c, the whole system won't work. It's essentially a "fail unsafe" system.
It's also useful to have a landline as I've used it to fax documents at least once a year for various reasons. I know there are sites that donut, but having it on hand just makes it so much easier, especially when starting with paper, which I always was.
Anyway, I'm not arguing your point, but I feel like people, especially with small kids, should give landlines more love. We have FiOS and it essentially comes with one that you can't pay less to not have.