I really loved the concepts covered in this video, but the use case for high key lighting isn't immediately obvious like it is for low key lighting (this video shows many dramatic examples of low key lighting which is a common look in cinema, but there's only one short clip from Midsommar to give an example of high key lighting).
For me, the first thing that came to mind was Wes Anderson films. There are usually virtually no shadows in his films as the entire emphasis of his filmmaking is placed on the composition and colours of his scenes. I think this is a key takeaway for how to effectively integrate high key lighting – if your lighting doesn't serve compositional purposes, then the objects in your scene itself probably should.
Would love for others to share effective examples of how high key lighting can be used cinematically!