All the Light We Cannot See

I had big expectations for this book, with it being set during the war. The elements are there. A blind little girl who lives with her father, being forced to fleece when the nazis invade their city. A young German boy whose gift is to work with electronics, and that's the use the nazis give him.
I expected way more of their encounter but it felt very underwhelming. Also the language throughout felt very PG-13 for a book set during the war.
The way it's written never captivated me and it took me months to finish.