That's a good question. I think that "childish games" is specific genre. These games have a certain audience of players. TBH I don't know much about Skylanders and Disney Infinity. But overall such games had some stagnation and as a cosequence they saw some decline in terms of players. There was a moment between 2007 and 2011 when there were a big number of titles based on movies. Probably Wii played a role in the expansion of these games. However, a lot of such games were mediocre at best. Batman: Arkham was a rare exception bit it initially was targeted on "hardcore" group of gamers. As a result, starting from 2012 there were less and less movie games because many of them didn't sell much. Then some studios decided not to care about this "childish" genre. For example, Microsoft cancelled the support of Project Spark (it feels like it could be Dreams but from MS) and there isn't Recore 2, and in 2020 Sony partially closed Japan Studio which developed Knack 1-2 and Gravity Rush 1-2.
If we talk about Activision then it feels like that they focused on COD and some Blizzard games in the middle of 2010s. That's why they didn't make Prototype 3, stopped a relation with Bungie and decreased support of Skylanders. They chose to focus on most profitable games like COD, Hearthstone and mobile products. Now in MS era Activision lost Studio behind Crash Bandicoot (it' s independent now) and it's just hard to say what will be with some other studios. MS reorganise some teams now. It won't be shocking if some of Xbox Studios are gonna become COD support teams like Raven. I won't be surprised if tomorrow MS will announce that 343 will help with COD games. That's why I don't expect the return of Skylanders.