MK8 and ARMS had a similar amount of content when they launched. If anything ARMS comes out on top.

Splatoon 2 had a 5 hour story mode/tutorial, Salmon run, and dress up. There is definitely more there but I wouldn't call it significant. It's probably not you but a lot of people don't realize how many maps were added since the game launched.

The reason people didn't like ARMS is because they didn't like the game period. It wasn't due to a lack of content.

If those games are worth $60 totally depends on how much you like that sort of game and how much you're willing to spend, but they're in the same ballpark in terms of content imo.

Looking back I wouldn't have paid more than 20€ for Splatoon 2, but that doesn't mean it should have been a 20€ game. It's a great game and it's definitely worth the 60€ pricetag, it's just that it's not my type of game.

It's frustrating seeing people say a game isn't a full game or it's lacking content when in fact their problem is that it lacks content they like.