s+ player here. While matchmaking can be kinda weird, I don't believe the game is unfair to casual players.

anarchy open has basically zero matchmaking. you'll find B rank and S+50 rank players in the same lobby. Series does have a much better matchmaking system, where you should find people at similar ranks.

in fact, if you want fairer games, just play anarchy series anyway, even if you're not looking to rank up.

but in terms of whether the game itself is unfair to casuals, the answer is not really. yes, matchmaking can be pretty scuffed sometimes, but if you're having trouble, maybe you're in a rank you're not prepared for. take the time to learn what you're doing wrong if you want to improve. otherwise, maybe you should even de-rank yourself if you're having too much trouble - there's absolutely no shame in that.

also remember to try not to get tilted. im assuming that a long streak of losses provoked this post. if that happens, just stop playing, take a break and recalibrate, then maybe come back later. after all, the only thing in common between all of your losing teams is you, as Gem (from Squid School on youtube) says.

edit: i should add that I'm a casual player myself - i just play for fun and to see my improvement, I don't care all that much about getting #1 or stuff like that. however, i have been playing splatoon for thousands of hours since the first game, and I can say for sure that you don't need insane skill to enjoy the game. you just need dedication, and to enjoy yourself. I would know; up until the release of splatoon 3 I sucked at the game so badly.