You're right, that is blunt and dickish. But that's cool, you're probably absolutely right, and this game just isn't for me.
I must call bull to you "knowing" he has plenty of even matchups though. Seems to me like there isn't much 'getting better' I can do in the face of him having an overpowered move with crazy fast startup and an insane hitbox that gives combos for free all day in response to and in punishment of pretty much everything.
That move is excellent, but there's a lot you can do, it's very negative on block. If he's using it at max range it can be hard to punish, but off the top of my head Flash gets a free hard knockdown and mixup, Raven gets a free combo, Deathstroke gets machinegun, Superman can super, Wonderwoman can stance cancel to shield charge and be at +13 in his face, Bane can get right through it on prediction with lv 1 Venom for twenty to thirty percent and a hard knockdown, Green Arrow can Ice Arrow and get full combo (If he had it loaded), Grundy can ex-swamp hands for full combo, Aquaman and Nightwing can seismo for full combo. . . the list goes on.
Basically the trick is to not jump, and to make sure you punish it whenever he whiffs it or you block it. Move in on him using block dashing if you are playing a RTSD or keep fullscreen (where it doesn't hit) if you're zoning. At medium range he only has three moves he can do the grab, which we saw above leads to punish, he can try to push you out with minigun (Which wastes a bar he needs to combo off the grab) or he'll go for B+1. B+1 is going to be followed by an overhead or a mid, if you play someone with a parry there's a gap there you can parry in, if you don't block low then high, and wait, he's either going to trait cancel grab or not, and he has to do it quick, you can full combo punish either on reaction.
Look, I found the matchup frustrating too, so I started looking at it. That's what I've learned just kinda recording him flowchart in training mode and seeing what I could do to get in and hurt him. He controls a lot of space, but it isn't safe unless he is at absolute max range and even then it's unsafe to all the stuff I listed above. So consider any of those characters decent counters since they strip even max ranged safe lantern grab. Just remember he wants you to jump, so don't. Also he'll try to grab dashes, but if you only dash when he is in recovery from gunshot/minigun/missiles then it's safe. If he isn't using his zoning tools, then you're free to counterzone or hell just walk up to him.