My Galaxy Note 8 camera is nothing like you described. You don't have to unlock the phone, just double-press the power button even if the screen is locked and i

My Galaxy Note 8 camera is nothing like you described. You don't have to unlock the phone, just double-press the power button even if the screen is locked and it goes directly into the camera app, ready to shoot. You can even review and delete photos in this mode. If the phone was locked, it only shows the photos that you took in that session. Latency is barely noticeable. I always take multiple photos anyway, either a burst or by tapping the shutter button repeatedly. I never dared do that with a film camera except for very important shots. So I get a lot more interesting shots now and a lot more "keepers".