Thankfully shortly after release there will be an upgrade to eliminate the notch if you so desire.
Phones need to keep the screen size manageable for one hand use...bigger screen/notch less bezel but the phone is still the same size...
...if I were OnePlus I would have kept the same 6.01" screen and made it even less taller. They shaved off only like a 1/2 a mm since going with a slightly bigger screen. Could have been 150/151mm x 75mm x 7.7 mm with the same screen size as last year.......