I don't know it just not fun.
For marine it only fun when it gets stalemated a bit and you can try to call that great CAS or try to organize a flank but when it non-stop rolls on either side it just not fun. And, no I rather not just go mindless marine and just rush aliens. If I wanted to do that I could play any other game like Squad or Rising Storm or Planetside or Natural Selection or... you get the point. I could go also on that shipside roles just feel awkward or useless these days, medical won't get used much since any serious damage is more rare, supply wont get much use in short rounds and/or you won't really get anyone to the req-line anymore so you don't even have the rush for something interesting or late game pfcs, and engineering doesn't even have power and tbh if you roll an other OT guy might as well cyro and if you get an other OT guy that is assertive might as well cyro because you aint going to do shit fast and if you are a background OT it just going to feel pointless as no one will want anything you produce anyway. And, even command feels utterly pointless, it literally just there for RP and is totally unneeded. Marines will just do whatever they want, which means metarush the known meta locations without a care in the world largely because if 'xo or co or whomever in command doesn't order all four squads to rush hive no problem', not much it matter since all of the xeno stuff been gutted including age.
For alien, it just pure aids. If your robust at any degree and don't go combat tier 3, dont even bother with that boiler shit the XXs get that, you actively hurt your team. Hell warden practically hurts the team due to lost of combat potential. It just feels the endless nerfs and changes to tier 2s and how harsh it is to capture anything short of tacklebanging someone to death just makes it hyper tier 3 focused. Doesn't help that a carrier literally is better off putting a trap down and capping rather then direct capping by applying it, it doesn't help that if any alien caste seems to have a lick of usefulness it will be nerf hammered so hard it aint even funny( shit we still have double-triple PB buck, is it so god dam hard to just put a global CD on the player for PB or something?), it doesn't help that survivors been buffed with all having a shotgun and buck meaning if a gang of robusto survivors exist goodbye all your tier 1s and 2s and future tier 3s, it doesn't help that you will 100% get rushed by marines and that you have no insurance you will get a hivelord or drone willing to or mentally able to build anything or even have a queen which doesn't speak Brazilian, not that building matters since the buffs to OBs made it building anything is literally pointless since it will be OBed and deleted from existence in a microsecond.
It just sucks to go anything, it literally only based on PFCs rushing the hive and killing aliens nothing else. Command, req, medical, engineering, the capture loop, any sort of challenge with tier 1s-2s nope. Just PFCs rushing hive as fast as possible matters and god forbid anything slows them down or attrition them. Aliens need to kill every last one of them and win groundside in 5 milliseconds and marines have to be able to clean house in 5 milliseconds if your crop of tier 3s die, no expectations.
The game is not fun