Over 3 decades ago, when I built my current home, I wired up for a phone in the Master Bath Toilet room......we called it the "Throne Phone"......it used to hang on the wall right next to the toilet. Just a blank plate there now, as we no longer have a landline.
I didn't use it much at all, but it was handy when you were expecting a call, and you were in the Bathroom......not necessarily taking a crap! Or at night (in bed) when the phone rang, and it was family.......back then, the battery/cordless phones weren't that good.......especially in a large home, where the base was too far away.