The first thing that comes to mind is anything related or connected to the smart phone. Music, movies, camera and apps.
As far as I can remember, the music cassette was my first memory of music. My first ever cassette was 小虎隊 - 蝴蝶飛 single that my mom bought for me at the 7-11 across the street when I was living in Taiwan. Second was Will Smith's Big Willy Style/Gettin' Jiggy Wit it a few years later. I never got a Sony Walkman, most of my listening was done at home.
Jump a few years and it's the CD player era. I won't go into nostalgia about my first CD player, but those born after the iPod era, will never know what it feels like have a song skip when you're running to catch the bus/MRT. I remember eventually buying an anti-skip Sony Walkman CD player with a metal lid.
Mostly at home has seen the biggest change. Video rental stores like Blockbuster in the states and a lot of comic book/tape cassette/DVD rental stores are going extinct in Taiwan.
Of course how movies are shot and the originality of a lot of the movies lacks after CGI came along is something they'll never experience. I didn't grow up in the 80s, but am a big 80s movie fan.
Those born before the digital era may have not even known what a tape cassette or one of those rewinders looks like or why we have to rewind tapes haha
They may never know what it was like to have a limit of 24 shots to a camera and to not pull the reel past a certain point so it didn't expose light to it!
There's like a million things that apps have replaced. For some reason, I can't think of anything aside from "road maps" being replaced by Google maps. I don't remember the last time I opened up a paper map in the car to figure out where we're going. Real time traffic updates and Google giving me the fastest route with no highways and no tolls really really makes no use for a 4-10USD road map.