I remember landlines fondly, it felt like I could hear people better back then. At the same time, I also remember the 4khz cutoff. It was the reason music sucked over landlines. Like if you were listening to music with a friend from highschool over the phone, it'd have no depth and you couldn't understand half of it from lyrics to beats. Hold music was a lot worse back then, these days it doesn't sound near as bad.

I think for a lot of us later Gen-X and older Millennials, as we age our ears don't work as well as they used to. Especially those of us like me that didn't heed good ear protection. I can't speak for everyone, but I suspect if today me tried to talk to someone on a landline back in the early 90s it'd still suck as bad as it feels like it does with cellphones today. We get more range with our phones now but our ears have a harder time processing it.

Just a thought.