NO REST FOR S.H.I.E.L.D.
One of the many superlatives fans appreciate about Agents of S.H.I.E.L.D. is that there is no status quo and the show is constantly soft rebooting itself. The series and its characters are in a constant state of flux and upheaval. From discovering that S.H.I.E.L.D. was HYDRA all along, learning about the existence of Inhumans, new directors placed in charge, journeys to another planet, and even meeting Ghost Rider, the Agents of S.H.I.E.L.D. are constantly careening from one crisis to the next and forced to adjust on the fly. There's no such thing as 'a normal day' when you're a part of S.H.I.E.L.D.
Season 4 saw the series toy with its own history, bringing back popular dead characters like Antoine "Tripp" Triplett and Grant Ward in the virtual reality world of the Framework. While borrowing the concept of The Matrix, this was also S.H.I.E.L.D.'s version of "Flashpoint"; its own alternate reality "What If?" the-world-is-upside-down tale where HYDRA controlled America, some of the Agents like Melinda May and Leopold Fitz were not only complicit but were part of HYDRA high command, former enemies like Ward were now freedom fighters, and other main characters like Coulson were not part of the fight at all.
The Framework story was a funhouse mirror version of the S.H.I.E.L.D. fans had come to know, and the series spent several surprising and satisfying episodes within the Framework exploring all aspects of this weird, false reality. Then, literally moments after the Framework story and season 4 were over, the Agents of S.H.I.E.L.D. were kidnapped and rocketed into the future.
S.H.I.E.L.D. V FLASHPOINT
When it comes to stakes, Agents of S.H.I.E.L.D. aimed as high as possible with their time travel saga: literally, the fate of the world. Thus far, the entirety of season 5 (save for one episode told in flashback of how Fitz managed to join his friends in the year 2091) has taken place in the future. The series then introduced the idea of at least one alternate timeline where the Agents have already traveled back to 2018, failed to prevent Earth's destruction, but helped enable the circumstances of what they would find when they are brought to the Lighthouse space station of the future to occur. It's been a trippy, ambitious, and bravura season so far - arguably S.H.I.E.L.D.'s best-ever long-form story that is confidently building to the 100th episode, which promises to 'shock and destroy' its dedicated fans.
In "Flashpoint," though Barry Allen altered time, the scope of the changes were narrowed to how it all affected Barry and his close circle of friends and allies. The rest of the universe in Flashpoint was the same as it ever was; and if it wasn't, we weren't in Flashpoint anywhere near long enough to really delve into how different that timeline was from the one we were already familiar with. Still, the fate of the world, much less the Multiverse, was never at stake in "Flashpoint" - there wasn't even really a villain truly threatening Central City, despite the presence of a new evil speedster called the Rival. (Barry was the true "villain" of the story.) Everything was kept within the confines of the bread-and-butter of the series: the soap-opera drama and pleasing comedy of its main cast of characters. "Flashpoint" was ultimately undone by its curious lack of ambition.
At this point in its run, with no guarantee of a season 6, Agents of S.H.I.E.L.D. is going for broke and telling as colossal a story as its ever told. With nothing left to lose, S.H.I.E.L.D. is emptying the chambers of his considerable firepower and the results now see S.H.I.E.L.D. hailed as the best reviewed Marvel series. Even despite the fact that Agents of S.H.I.E.L.D. is still ostensibly part of the MCU, the series is now flaunting its tertiary, tenuous-at-best connection to the rest of Marvel's shared universe by going ahead and destroying the world, regardless of what is depicted in the movies. By now, Agents of S.H.I.E.L.D. is the master of its own fate and rules its own corner of the Marvel universe.
The Flash could have used some of this same "We'll do what we want" attitude when it presented "Flashpoint", which was exactly the kind of story that requires vaulting ambition. Rather, it was hamstrung by its preset limits to remain recognizably the same series it always was. "Flashpoint" only fleetingly disrupted not just its own reliable status quo but that of the rest of the Arrowverse.
The next time The Flash decides to take on a time travel epic, hopefully, the series will make a braver and bolder attempt to break its own mold and do something really special. After all, they now have Agents of S.H.I.E.L.D. season 5 as a role model.
Marvel's Agents of S.H.I.E.L.D. airs Fridays @ 9 pm on ABC. The Flash airs Tuesdays @ 8 pm on The CW.