Of the first 10 non-dice images in the 2024 PHB there's 1 that's 'twee.' there are nine that aren't, including a couple that are brutal.
Chapter two has 8 images that aren't icons. Zero are twee.
Chapter three has 14 icons and 29 other images. There are four of five twee bards and a single twee druid. No twee are anywhere else.
This so called "pivot to twee" isn't backed up by a survey of the art in the official books.
There may be a perception, because people tend to latch onto things they don't like in a way that makes it so a mind can't forget it. There's no real, actual pivot.
What we do know is that Stranger Things, Critical Role (and other actual plays), Ghosts, Magic tie-ins, the D&D movie helped 5e surge. None of these things were embraced by unchanging traditionalists. All welcomed new players to the table in a way that this hobby has traditionally struggled with.