In my opinion, Enterprise had a lot of potential, until they introduced time travel. That’s when they lost the series.
They could have done a lot, like showing some of the subtleties of Vulcans or Klingons. I think that would have been popular. I give them props for revealing the dirty tricks the Vulcans played on the Andorians.
All of the series used the concept of time travel, but you are right, the way they use that aspect fouled the series on that turn.
The final season of Enterprise, after they finished all the silliness of the temporal cold war, is really when they clocked in. It finally really became a prequel to TOS, stopped introducing races we’ve never seen after (before? whatever) and started building the federation. Then it got canceled and Braga handed in the worst final episode ever. But until then it was really good.