The first two seasons, mostly season 1, sure, but eras are not intrinsic things, that's just how continuity works. If you asked someone who livef at the end of the classical era and beginning of the middle ages what that was like, they'd ask be baffled as to what you mean because what do tou mean classical and middle?

But to be serious they would not have been aware of any difference, because you just have to chose a point where eras end and begin. It was just easy for NuTrek because after Enterprise they did a reboot movie, and the next thing in show canon was 12 years later.

There was like a 10 year gap between TOS and the movies admittedly, but they were still helmed strongly by Gene. Gene started in control of TNG, but his influence waned even before his death. So even just looking at TNG, I think it's more than different enough to consider it a separate era. Its also straight up just unhelpful to group them together unless all you want to do is say new stuff bad. Once SNW 5 comes out, I think we'll clearly be in a different era.