The issue with the atlantis is that it doesn't really have a roll to fulfill in lategame uef navy. Uef doesn't need carriers as much as other factions since shieldboats make sure cruisers don't die quickly anyway. Meanwhile you use torpedo boats as defense vs subs. The most use i've gotten out of atlantis' is when using it as some sort of bulky sera t3 sub do get value by damage over time. A big issue of sera t3 subs when trying to get value from them is that they are so easily killed. Your opponent can just send 5 torps to kill it and the insane aa that they have isn't too relevant when they die to torps in 1 pass anyway. The atlantis meanwhile just ignores those torps because of the insane hp it has, but trades of by not having great dps/mass and mostly being insanely slow, which leaves the main reason why atlantis' are bad: groundfire by battleships.
If atlantis were unable to be groundfired by bs's they would most likely be way too strong since you can stack a lot of them with no proper counter. A few suggestions were made in some balance call a few months back but other things had priority over a uef t3 navy adjustment since even without atlantis it's already pretty well balanced.
The few suggestions i remember/can think of are:
- Give it the reverse shieldboat treatment by decreasing its size a bit and making it more manoeuverable
- Lower it's depth in the water by just a bit. Not enough to make bs unable to groundfire it but enough to make it harder to be groundfired. Currently even fobo's can groundfire an atlantis which means they are insanely close to the surface
All in all even though atlantis aren't in a great state atm it isn't a very big issue and therefore it's not being worked on.