I only ever use it for Splatoon 3, as of now, and it’s pretty useful. The shop can help me get rare gear you usually don’t get elsewhere, like the Red Battlecrab Shell. Being able to see the catalog is pretty cool, and I don’t have to check my Status section in the menus. Wandercrust is ok, the Stay Crusty cap (and maybe in the future, any other gear) is ok at the very least, but it wouldn’t remove much if it were removed. This is the only time you can see more Salmon Run stats more elaborately, and it warns you better than the ingame menus, such as Wildcard Rotations. As of now, we have only had 2 Splatfests in the full game, Gear vs. Grub vs. Fun, and Grass vs. Fire vs. Water, and it’s nice you can see who won and all the points. It’s really useful that you can see what your friends are doing, especially when I’m trying to host a friend game/private battle/league battle (in the future), and they aren’t joining. Overall, this is WAY better than Splatoon 2’s, which was a more Cluttered mess. I don’t have any other games with it, but I’ll take other reviews’ word for it. It’s ok, but not perfect.
Also, before you ask, I don’t really use voice chat, I have my online friends on my contacts, so I’m not sure about the quality.