Throughout human history, technology has changed slowly. If you were able to take a person from 1000 A.D. and put them into 1200 A.D., they'd be fine. They'd recognize everything and feel that the world was similar to the one they'd left. If you took a person from 1821 and put them in 2021, though, it would be chaotic. They wouldn't recognize anything. They'd have no idea what a computer was -- much less a smartphone -- and they'd assume the world was far larger than it really is. Medicine, transportation, communication -- all versions of technology would be staggeringly different.