It wasn't just the hopper character though.
The children were all children together in s1 and 2.
S3 there was all this stuff about how boys and girls are super different, dying understand each other, aren't honest with each other etc etc
That felt to me like a really modern take. I was their age in 80s, am probably exact match. There was sexism but it was different, the stuff with the journalist woman and the horrible men felt right. But the stuff where the girls and boys are different species in early teens, no. It wasn't like that, that is new.
Also science was kind of cool then. I mean terrible films some but weird science, back to the future, flight of the navigator, ghostbusters, war games etc and so on, there was a lot of excitement about science. The teacher would have been cool with all his stuff in the garage, as in fact he was more in S1 I think it was. And it seemed that, as in the 80s, with Joyce, the kind clever science guy would be the man for her. It felt like they were going there then changed their minds.
While watching I really felt they had chucked the pretty authentic 80s stuff out the window and gone for a load of more current, and to me, objectionable stereotypes and tropes.
Yes I may have overthought it.
I was also annoyed that it was so so much more violent than the other series.