With the release of Splatoon 3 coming up I figured I'd put down my unnecessarily long explanation of what I think made Splatoon 2 uniquely enjoyable to me, even though I can't stand other competitive team games. Maybe this will be useful if you're considering getting into the game with the release of Splatoon 3. Maybe it won't, I don't know, it's not an actual review and Splatoon 3 isn't even out yet.
Basically, there's a couple of design decisions in Splatoon's solo online play modes that seemingly make it worse for serious competitive play, but make it (in my experience) much more fun for somebody who doesn't take rank too seriously. These are:
1. Team composition is completely random
There are no picks or bans, no team requirements, and no opportunity to change your loadout once you've got your team. You just pick a weapon before queueing, and get put with three random people, regardless of what they're using. This is, of course, terrible... but it's not a complete disaster most of the time. Splatoon doesn't have hard-set roles or classes for its weapons. There's no e.g DPS/Tank/Healer distinction like in Overwatch, mostly because everybody has the same tiny health pool and every weapon kills in under a couple seconds at most. There are community-defined roles in competitive play, but they're more playstyles than anything concrete, and often quite flexible. Team composition is important competitively, but when neither team has the ability to assemble something meaningful, whatever you get thrown into is going to be viable, if not necessarily advantageous.
The upside of this is that there's practically no meta in solo play, aside from some weapons being slightly better than others and good luck being better than bad luck. No one weapon can get too popular, because even if it's really good it will more often than not be more or less completely ridiculous to have two or three of it on the same team. But you do end up in completely ridiculous teams, and that's half the fun! I've played games as the only short-range weapon user in a room full of the long-range, instant kill, laser-sighted "chargers", which is a bit like one of those overly elaborate heist things; games where we're all using the "Booyah Bomb" special that charges your teammates' specials when you use it, so we could loop the charge bonus and fire them pretty much constantly; and several games where everybody on a team picks the exact same loadout, which is just absurd. You truly never know what you're going to have to play with or against, so every match is fresh and you've got to improvise a strategy for every game on the fly, but that's made somewhat more difficult because...
2. Meaningful communication with your team is impossible
You have three "signals" you can use to communicate: "This way!", "Booyah!", and "Ouch...", which replaces This way! if you are currently dead. And that's it! Aside from mashing ZL to flop on the ground and make a horrible noise, there's really nothing else you can do. Practically, it's clear why Nintendo would do this: Splatoon is meant to be a kid-friendly game and you save a lot of effort on moderating chat if there's no chat to moderate. But it's interesting that even in Splatoon 3, you're still limited to just these signals. Left and right on the d-pad are right there, next to the up and down buttons for the other signals, there's nothing stopping them from adding "Sorry!" or "Oh no..." or "Look out!", and yet they have not.
This is pretty terrible, but to me, this really makes it seem like limited communication is a deliberate design decision. It does more than just make it very difficult to actually be toxic; the limited communication leads to a particularly impulsive style of gameplay. It's basically impossible to plan anything or give your team complex instructions, so you've more or less just got to react to things as they happen, and sense when to push forward or pull back as a vague ebb and flow punctuated by the occasional This way!. It can be annoying when your team isn't properly organised, but you can never really blame them for it. And when you do get a team that somehow works together, where you can charge forward as a unified front, cover eachother's backs and split up to maintain control of the situation when needed, it's the same magical feeling as doing well in games like The Mind, as if you're communicating telepathically.
I'm sure that the benefits of these decisions mostly disintegrate if you actually, like, try to take the game seriously and climb in ranking. If you want to win reliably, yeah, unavoidable team composition RNG and difficult communication would probably be somewhat frustrating. But if you're like me and just want to try to win every match and enjoy the attempt, Splatoon being terrible is what keeps it fun.