I third the whole "abilities are useless" thing. They destroyed Run Speed, Quick Respawn, Ink Recovery Up (I believe this one now has slower recovery times in exchange for slightly faster ink recovery when not submerged), Ink Resistance (stacking is awful), Cold-Blooded (was killed off with the 50% decrease from 75% in 1, stacking and less tracking items worsened it), Haunt (only you can see them through walls, really?), and Stealth Jump (might have been needed, but still, wasn't the ability, was QR and SJ together). Quick Super Jump was never good and all the new ones are utterly useless too.
Bomb Defence does absolutely zilch to help, I stacked 2 mains 2 subs of it when everything rated it as "it's SO effective against Inkjets" and still got destroyed by them and only Burst Bombs get a true counter from it. Object Shredder works on Ink Armor (got nerfed so irrelevant perk), Baller, Splash Walls (only like 4 weapons have that and most aren't used), Rainmaker shield (again useless) and Bubble Blower (with the buffs it is useless on your team's, only good for trying to counter enemy bubbles). Drop Roller is terrible for many reasons, Stealth Jump doesn't work when the game is all about close range and small maps, so proximity to see the jump is guaranteed and a waste of a slot. Thermal Ink only works if they are in human form (and most people stay submerged so useless, plus short range meta so even worse), Ninja Squid still has uses I guess, Haunt was killed off majorly (they should buff it to leave the echo mark 1-style and let the victim see them through walls until that player is killed) and Respawn Punisher is useless.
Tenacity is still a decent choice, combining that with a weapon where you stay alive more than your team and the auto-charge mechanic of Ranked and you have a better way of getting specials than you do by piling up Special Charge Up or Special Saver. Comeback is great because you get 4 subs of






for 20 seconds after respawning. Opening Gambit is still bad due to being a dead weight for 4:30+ or 2:30 since you only get 3 mains of Run and Swim for the first 30 seconds, and with Run Speed nerfs it helps no-one. Last Ditch Effort still retains its activation when the enemy team reaches 30 and lower, and gives you 5 subs of




(data is coming from the Wiki), so for ink efficiency it's great, but the QR perk is useless in this game, but as we all know it's very situational and is usually activated too late to make a difference unless you're playing Rainmaker or Tower (or in 2's case Clam Blitz).
This leaves the stackable abilities, which I've covered







. Ink Saver Main and Sub are still very useful, and are pretty much my exclusively used abilities. Swim Speed still works out nicely so I squeeze that on when my weapon doesn't need as much ISM and ISS. When I play faster weapons like Dapple and Splash I usually go 1m/3s Run Speed and Swim Speed with Comeback and it works out quite well. I tend to go for Comeback and Tenacity so Special Charge and Saver are out the question for me (and they usually are wasted slots anyway) and I haven't any use for Sub Power Up yet (there are 1 or 2 weapons coming down the line where I could use it) as I don't need further bomb range and the perks for other subs aren't worth it excluding Splash Walls (a hint for one weapon I want to use it on :P). Special Power Up seems cool for Bubble Blower, but that special is underwhelming, the faster activation for Ink Armor is great but situational and requires at least 2-3 mains worth to be useful and the larger explosion damage radius is nice for Splashdown and Baller but I never have need of it. So my ability selection is nothing more than






. It's great for investing in to for avoiding ink issues (I use a lot of ink heavy weapons, SSPro and Hydra for example) and combining with a small amount of swim speed works wonders. When I occasionally feel forced into being boring and playing Splattershot I put on a small amount of ISM and ISS, Comeback and some swim speed. This is just my take on it, we all value some exclusive abilities differently but Tenacity is amazing on weapons that won't lay as much ink down like Hydra & Rapid Pro (more crucially ones that stay back and alive when the team goes down) and Comeback is nice for the constant 20 second boost to get back (I benefit from it quite a bit anyway).