This has nothing to do with tick rate, though.
Yeah, I know. This is just another reason the first game feels better to play than the second.
Well, I disagree about that. Personally I find the first game too broken, too simplistic. I know no one else feels this and maybe it really isn't true, but I can swear the hitboxes for everything feel so much smaller in Splatoon 2. It's just a lot harder to land shots, with any weapon, and this makes it more engaging for me - more skill required for splatting means more engaging gameplay, and less random deaths also means more fun.
I mean going back to Splatoon 1, it's ridiculous just how easy it is to be killed by just about anything. If there's a charger aiming anywhere near you, dead. A roller swings near you, even if it's at an awkward angle and some distance, dead. Someone shoots at your direc... dead. In Splatoon 2, it's much more often that I manage to barely escape death, and it's also much less often that I get splats. It just feels a lot better in my opinion.