But Junkrat is already useful in some maps. He's also one of the most picked characters in the lower tiers.
I'm not a particularly high tier, and I never see him in comp. And I could probably count the number of effective Junkrats I've seen on one hand. He's slow and his hitbox is fairly large for such a skinny dude and his mine isn't practical as an escape option. Most importantly, his projectile speed is slow enough his shots are arguably the easiest to dodge. He has his very niche uses, I agree, but I don't think there's any character in the game I wouldn't feel fairly confident taking him out with on average. He's pretty weak right now imo. At the very least, he's nowhere near as good at area denial as other characters are at area control.
Putting traps all over the map hoping that someone gets caught in them doesn't sound fun or reliable, it's random by nature.
Um....no? Not unless the player placing them is just throwing them out randomly themselves, but that's improper usage. I tend to place them right next to choke points or off to the side in popular fighting areas. It's about trying to find a middleground of a place where enemies are likely to be, being likely to follow through on the trap and places where it won't be spotted by enemies. The problem is that a single trap covers a very tiny area of any map. Given that the trap is little more than an annoyance unless you follow through on the kill, having more of them seems like a sensible buff to me. Hell, I'd be willing to take some damage off it in exchange, if that's the issue, even though it only does 80 already.
On the enemy's side, traps are visible in all maps, though some more than others. They have a set of jagged teeth sticking out of the ground. So it's up to the player to be aware of their surroundings and spot those teeth. Once you see it, you know that you either have to destroy it or that area is a no-go area, depending on circumstance. With the way the maps are designed, rarely will you ever be truly trapped with no options.
They can be annoying as hell, yeah, because some characters (like Tracer and Genji) are meant to move fast through an area, so they are going to be more susceptible to running into them. But all other characters have a reasonable chance of spotting them before they become an issue. Plus there are abilities that still let people protect themselves in some way. Orisa can Fortify and walk through it or put up a shield, as can Reinhardt and Winston, D.Va can DM, Genji can reflect, Mei and Symmetra can wall, etc.
And failing all of that, every characters can still primary fire and use offensive abilities, so everyone will always have a chance of just outfighting the enemy. So it's definitely not random, and I don't see how it would be gamebreaking either.
Edit: Also, Junkrat can't throw them very far. So whereever he leaves them, he has to physically go be at that location. So if you win a team fight, you're not gonna have to worry about them being in good areas again until the enemy retakes the point and Junkrat has time to set them all up again. And he won't set them up at all if you manage to kill him in the team fight and he has to run back. It's like Torb's turret, the less time he has to set the traps up, the less of a problem they are.
Yea, they were doing Barrierwatch with Bastion. Had to switch to Junk to counter that cheese.
Sombra EMP would have slaughtered them just as easily, or even Hanzo's dragons or a Tracer bomb, or Mei Blizzard, or Grav. Hell, you probably could have Zenyatta ulted and just rushed it, they wouldn't have been able to kill you. If you waited for Orisa's barrier wall to go on cool down, you could have shot D.Va's ult in there and they wouldn't be able to do anything about it. It's hard to think of a team comp that couldn't have broken them apart with them clumped together like that. Doomfist too if he was out now.