Caustic is INCREDIBLY WEAK right now!

The gas is supposed to function as an area denial, to slow down fights and to DEINCENTIVIZE enemies from rushing through gas. 
But against AVERAGE players it doesn't even do ANY of those things. 

Players know the gas damage is basically irrelevant because in the time it takes to KILL someone in this game, the gas has done a whopping total of 5 damage...
Yeah.... if they can push gas, take 5-10 damage and WIPE you, they will just do that. 

General problems: 
It only works on an illusory level against low level players, meaning it "works" under the illusion that they are scared of it because they don't know how useless the gas is yet. 

A single Maggie or Fuse Tactical can bust ALL of your traps in a massive area easily. 
Nullifying the whole idea of being able to control any position. 

The only thing the traps do well is block a door for 5-10 seconds. And barely even that. 

The traps can literally be placed, inflate fully to completion and then STILL be INSTANTLY destroyed by a Fuse Cluster. Where they won't even emit ANY gas despite being fully inflated before getting touched by any damaging projectiles!
This means that the TIMER for when the trap is "READY" needs to be DECREASED!
Because visually it is READY, inflated, and completely motionless and then still just vanishes in a second. 
This of course makes traps mostly useless to throw down mid fight in 50% of scenarios. 

The Gas ultimate has major problems with vertical surfaces, with its tiny size being almost useless, and the INSANELY CLEAR visibility THROUGH the ultimate!
Why should the enemy get to see CLEARLY THROUGH a Caustic ultimate? This destroys the utility of the ultimate as right now it is too weak to do any damage, too weak to deincentivize pushing enemy teams, and its problems with slanted or vertical surfaces makes it useless for 85% of situations. It is ONLY useful if an enemy team is LITERALLY in a corner of a room. 
In all open areas it is useless, a SINGLE THERMITE will do more damage to a full enemy team behind cover than a caustic ultimate will. 

It is TOO WEAK to force teams to move out of it!

The damage should absolutely start at 10 and then dramatically increase much faster!

The WHOLE POINT of the enemies abilities to destroy traps by shooting the bottom OR simply pumping damage into the trap exists to nullify the threat of a trap which is fine. 
But the traps are WEAK ANYWAY. So they don't even NEED to pop the traps! That's how bad it is!

The traps NEED to be strong enough for the whole mechanics of destroying the traps to have ANY MEANING of being in the game. 

Or if you want to KEEP them weak, then remove the ability to destroy them. 
It's one or the other, pick one. 
Make them strong, but able to be destroyed by everyone. 
Or keep them weak but make them NOT able to be destroyed and instead let them only vanish after triggering. 

The SIZE of the ultimate, vertically AND horizontally needs to be increased more than anything. 

Just an incredibly weak legend right now in the Meta and against almost all other legends. 

Gas barely blocks line of sight which destroys a lot of utility. 
And their biggest use is almost as cover in a fight, where you can use it as a limited shield. 
That's it. 

As far damage goes all gas is ACTUALLY useless. 

And lastly, to prove my point, I had a downed enemy CRAWL through the ENTIRE caustic Ultimate just fine, and then he crawled through several traps too, and STILL DID NOT GET FINISHED! 😂
I think if a DOWNED opponent with 100 HP crawls through a caustic Ultimate that should 100% do enough damage to FINISH THEM! 
At at the very least get them to down 5 health! 

Another change you could make is to add an initial HARD stun like the wattson fences to the gas. So that opponents are at the very least STOPPED in their tracks by the gas for 2-3 seconds. 
That could work to deincentivize them from pushing it easily as well. 

There, that's several solutions and all problems outlined, so yeah, PICK ONE and implement it 😂

And if you want reference for damage just compare the traps to Fuse Clusters size and damage rate. THAT is the type of area denial the gas traps SHOULD have! 
ESPECIALLY because a SINGLE Fuse cluster can destroy a whole room of traps. 
So the traps need to actually DO something if they can be countered so easily.