Small aside: why did Google choose to go the design direction of “childlike”? Gmail, iOS Chrome, other apps are just much slower-loading, clunkier versions from three years ago, with cartoonish animations and rainbow colors. Trying not to sound curmudgeonly.
They famously measure and test the hell out of everything (there's an anecdotal story about testing metrics for a shade of blue) and so at some point their numbers improved when they made those changes.
Bottom line: they probably sell more ads with those changes in place. That probably means that overall google's visitor to click more ads. SMH