Fringe was never the massive hit that creator J J Abram's previous show, Lost was. Lost had people gossiping about it between every episode, holding a coveted space among TV shows that would later be occupied by Game of Thrones, and I'm not sure any other show has really reached that level of saturation since GoT's finale in 2019.
In a lot of ways, Fringe had some things working against it. The parallels with The X-Files, perhaps not a water-cooler show (in part because it wasn't as serialized as shows of the 2000s were) but one that was a pop-culture phenomenon, were pretty obvious. And to be frank, I think that some of the show's early case-of-the-week mysteries were underwhelming, and in the case of its second episode, with the bizarre accelerated pregnancies, felt like too much of a "these sci-fi writers don't know anything about science" leap.
Basically, I think this is a show that's well worth watching, and while the first season felt better on a re-watch, it really isn't until the latter part of the show's second season (the episode "Peter" in particular) that the show starts to feel really, really cool.
As discussed on this blog previously, Fringe takes some utterly wild swings, and while I still look fondly upon the show's later seasons, I don't think any quite match the fun and exciting potential of its first massive world-shifting twist.
I guess we should do a spoiler cut.