Actually there´s a free one on their Eshop.... or sort of....... Mini Mario & Friends. The game is only playable with amiibos

That only supports the Mario amiibo, though.

I mean a game much like Skylanders or Disney Infinity that supports (besides maybe the third party characters) every amiibo, and features an interactive hub and all of that.

It probably would've sold like crazy if they released it back when amiibo were hot items that people were lining up at stores just to get them, but that's not the case anymore.

I dunno, I know I would've gotten a game like that if it were 2015, but now I don't care at all about amiibo anymore.

Lego Dimensions has a very impressive range of characters already, surprisingly diverse.  Now that Disney is (at long last) licensing their characters to Lego for the physical sets, it raises the possibility of Disney characters coming to Lego.  The Disney Infinity cancellation happened only a few weeks after the first Disney Lego toys were announced.  So far all the Lego Dimensions characters are squarely aimed at older gamers, playing up the nostalgia factor.  That makes it more appealing to critics, but it'll be hard to capture the Skylanders magic even with a hypothetical infusion of DIsney IP to skew younger.

Amiibo the onyl one that is still alive