If you're on the floor with 1hp and deadshot is at the other end of the screen then yes you are fucked. But the question isn't "What do I do now?!", it's "What have I done wrong that lead me to here?"
Comebacks actually do happen though. For example, 2 minutes in and of the first match Honeybee is down to about %20 hp where as Forever King still has his full 2nd health bar:
https://youtu.be/L-MWEDy3Brs
This video is also a good demonstration of how to handle a zoner.
Edit: Also, I'm not mad but frustrated at the fact that multiple posters have provided counter arguments but the belief that unless you zone, you can't win is still being tossed around as fact in contrary to evidence provided. My last sentence isn't an insult, it's a legitimate question.
Do you play FPS games? When the top player has x4 as many kills/points than you, do you give up and/or quit? I'm being serious here because you said the match should just end if you "can't" win.
To begin with, I didn't say zoners were unbeatable or anything like that. I think it's an uphill battle for many characters in the game, particularly those like Black Canary, mentioned by the OP. However I'm aware of the strategies to work around it. To clarify, I didn't say that, and don't agree with anyone saying it. Obviously zoners can be beaten, and by any member of the cast.
I do however think that on average, characters with good zoning options in Injustice 2 get an easier time than others. Which is why, thus far, we consistently see zoners winning tournaments. Because even if Black Canary can technically win every matchup, she has a harder time doing so, so when you've got to play through 32 players in double elimination, it's much less likely to happen if your persistently disadvantaged. Being disadvantaged does not mean that there's nothing you can do, I didn't say that at all, but again, I do think it's a harder game for non-zoners.
As for the FPS analogy, I've never played an FPS game where the game allows you to respawn into death because the other player is winning. There are certainly times where winning becomes unrealistic, but I can't think of any where it becomes near enough. impossible.
Aside some nonsense like Call of Duty nukes, which are pretty stupid and did not feature in competitive matches. The only similar experience I can think of is when you literally don't have time to win the objective, but it's not as clearcut as the wakehip chip of scenario in Injustice however, it's never obvious the person losing is going to run out of time. Plus there's still things the player can do to ensure it remains an interactive experience, even if you can't win the round, you can still control your character, earn kills, etc.
Providing examples otherwise doesn't mean that the example that exists is bad. I'm talking specifically about NRS, not other series. Every NRS game has had chip going back to MK1. The games are designed with this in mind.
But I'm not going to bother debating further since I disagree with everything you say and neither of us is likely to come to an agreement.
All you said was if it was something players didn't like, then maybe 'they' (Netherrealm) would have fixed it. By that standard, other developers had fix it, thereby suggesting it was something players didn't like. Nether Reals games don't exist in a vacuum, FGC members tend to play lots of games, and in many cases, many of the players that wanted means of dealing with chip death, likely also played Nether Realms games.
Ultimately, you omitted the qualifying statement in the initial remark (players of netherrealms games), a qualifying statement which in the context of this argument, doesn't make sense, in order to setup a straw man, and then decided rather than address that inconsistency you would remark that there was no point in debating further. Indeed, you are correct that there is no point in debating further, but not because we will not agree (convincing others of my opinion is rarely the expectation I see in debate regardless), but because you could not collect and present your thoughts consistently.
. I hope to compete more soon. I always feel bad asking Comp to play because I know he's got people constantly messaging him and don't wanna bother him haha. With that said if you're reading this Comp, I'm down for some sets tonight if you are lol. 
