Plus this ain't new to Zelda, it's pretty common for ancestors to look alike in this series. For example Spirit Tracks Zelda looks exactly like Wind Waker Zelda, and in the same game Linebeck the III looks just like his grandpa from Phantom Hourglass.

Yeah I know the "real world" explanation would simply be "it's easier to just reuse an existing model for an ancestor than make a new one" but hey it helps make it clear who's a descendant or ancestor of who. (Majora's Mask is a unique case of reusing assets though because that game famously had a short dev cycle due to a bet between Miyamoto and Aonuma, and they used the whole "alternate dimension" thing as a way to easily explain the model reuse in-universe)

But what about Granny-Loli Scientist Purah? She’s gotta be playable with Sheikah-Science as her weapon, CHECK IT!.