Spoilers below for anyone who has yet to watch The Flash's Season 3 finale.
For the entire duration of The Flash Season 3, it was hard to tell if the writers were crafting genuine conflicts or if they were just trolling fans with Barry constantly botching attempts to fix problems in ways that others explicitly warned not to do. And so, when the finale closed out with our bolt-chested hero near-necessarily volunteering to enter the Speed Force to restore the balance, feelings of dread were far more prevalent than those of success, and I can't help but think that Barry's big sacrifice is just going to make everything worse for Season 4.
First, let's talk about Barry himself, which means we're talking about the core character responsible for just about every act of destruction and distress in Season 3 (although we obviously weren't always aware that Future Barry was the one wreaking havoc as Savitar). To come up with a list of things that Barry has done successfully proves a much more difficult task than one might imagine, as he almost always chooses the road less traveled to fix something, never realizing that it's less traveled for a reason. For example, Barry tried all season to skip back into the past, and then ahead to the future, in order to correct a problem that was tangentially caused by him going into the past -- fool me once... -- and while it's certainly possible that Savitar's defeat only happened because of certain timeline changes Barry caused, Team Flash's victory didn't need any time travel to happen.
Beyond Cisco's ultimately destructive polarity-reversing tactic that sent the Speed Force into its initial uproar --and even beyond the fact that anyone could have just put a bullet in Savitar's brain when he was moping about S.T.A.R. Labs -- Savitar's big plot was ultimately foiled by Barry phasing through the suit and knocking the speed god nemesis right out of it, rending him mostly powerless. So the question immediately became, "Why in the hell didn't Barry just do that phasing thing at any other point when he and in-suit Savitar were in close quarters?" It's a question that fits in with others like, "Why didn't they hide Iris at A.R.G.U.S. in the first place?" or "Why did anyone tell Barry anything after they figured out that Savitar immediately acquired all of his memories?"
So we all know that it takes Barry a few dozen times to get to correct answers, and that's even exemplified within the finale after Savitar's dissipating death. Cisco didn't immediately deserve to get pounced on for disrupting things when he drew Jay Garrick out of the Speed Force, but everyone in Team Flash is fully aware that the a speedster's presence is required within the Speed Force at all times. How was it NO ONE realized that glaring error would need to be rectified post-haste? Barry was even overly comfortable and confident enough that he went on to re-propose to Iris inside their home, probably after taking a shower. WTF? And then a little later, while everything around him was going to absolute hell, Barry took forever making his goodbyes before actually stopping the chaos. Even a normal-speed person would have just immediately dove in to keep the city from completely being eradicated.
And because this is more about Barry, we won't even getting into the Speed Force itself taking so long to start reacting to Jay's absence. (Maybe it had to figure out which form to take in order to woo Barry the easiest.) He won't have as rough a time inside that most haunting setting as others, but Barry will almost definitely still be severely affected by it all. He won't be mulling on Iris' death, specifically inciting another Savitar iteration, but what if he's trapped in there for 15 years and starts to lose his mind? Another lunatic Barry does not a safe Earth-1 make.
Presumably, The Flash won't actually keep Barry trapped inside the Speed Force for a large part of Season 4, and the story will probably pick up with him escaping at whatever time, for whatever reason. (It would be interesting to see how the show would function without its titular hero, though we've already seen Barry take episode-long jaunts into the S.F. and other places.) But even without knowing all the details, how can Barry's absence actually make anything better for Team Flash or Central City?
Kid Flash and Jay will be able to handle some of the clean-up that'll need to be done just after Barry went away, and Harry's presence likely means Jessie Quick will also show up to help out, but what happens after they have to go back to their worlds? Iris won't have the love of her life around, so she'll be emotional. Cisco won't have his buddy around, and so relatively soon after their friendship had re-warmed, though he might be able to Vibe-hang on occasion. Joe won't have his other son. Wally won't have his mentor. The CCPD will be missing a CSI guy. And so on, and so on.
If anything actually will get better in the wake of The Flash's exit, beyond immediately stopping all those colorful lightning bolts, I can't really think of it. Sure, the team won't have to worry about constant timeline blips and blunders erasing people (assuming Wally doesn't decide to kick it up a notch), and it'll probably take less time overall for smaller problems to get solved. But those things aren't really what makes up a season of The Flash, so they don't count.
But maybe, just maybe, Barry will do something within the Speed Force that retcons the show back to [fill in a particular plot point], and then none of these worries will begin to bloom. But then that's an entirely different list to talk about. For now, we'll just say "Godspeed" to Barry. Definitely not "speed god," though.
The Flash is now on its big hiatus, and we likely won't see anything from Season 4 for another few months, since it won't show up on The CW until October. In the meantime, check out some changes we'd love to see in Season 4, and then peep our summer premiere schedule to see what new and returning TV shows are hitting primetime soon.