@Peri_Longbow_plzCaustic is pretty well-balanced, as his gas is less useful than other abilities when you use it in the open. It's still somewhat useful, but other abilities are much better.
Caustic is good in close quarters, but he isn't op level good. Many characters have some way to avoid it, or a way to counter it. Crypto has his ult, and his drone isn't destroyed by the traps. Bloodhound's scan allows your team to see the Caustic approaching.
As another thing, Caustic's gas affects his teammates too, so chances are if you are stuck, you'll only be fighting Caustic, and his teammates will be hanging behind the gas doing whatever. You can always just back out of his gas and find another way.
If, by some reason, you are forced to go through his gas, and you die, then it's not really Caustic. (Like if you need to escape the zone.) Wattson would do similarly well, as her fences will slow and damage you. Even if the enemy team didn't have a trap character, they'd still have a huge advantage over you due to positioning. They could sit in the safe area and gun you down as you try to approach.
Sending Crypto to a place with a click of a button would be okay. I'm just saying that it can basically only be that change, and they shouldn't implement the other one, or else Crypto would be too mobile.