I have a plain n simple phone attached to my landline, and it works without electricity......
No it doesn’t. It relies upon weak electrical current within the landline itself. It does not require an *external* source of electricity.
A nitpick to be sure, but this is why so many are making sport of that suggestion here.
I used to have an old Bell phone. It worked under any conditions. Problem is, even though I have a land line, it has all been upgraded to fiber in our area. Now the old phone does not work anymore. Just be aware that land lines aren’t going to be much of an advantage in the modern era.