Two notes here:
- McDonalds’s and others have moved towards more generic architecture as it’s easier to sell off at the end of a location’s lifespan; this is just business being business
- In terms of McDonald’s specifically, the US branch has been running from the brand’s “kiddy” image for decades, despite that by large being the main allure, and despite their attempts repeatedly failing. (See: the McDLT et al.)
Remember Shuffle ep. 72 (The Fries and Fall of a Midwest Princess) does a pretty good analysis of this phenomenon iirc