Putting your rhetoric aside, you're mostly right. As someone that maintained an old Java project, a NPE was the most common type of issue that I had to deal with. The code was riddled with them and business logic often broke leaving me to deal with lots of support tickets.

That being said, implicit nullability leads to mostly human type of errors and comes from our limitation to fit all the parts of a complex system in our brains. I'm curious if there are example where machines write code and use plenty of implicit nullability without that causing any NPE issues ever.

Just a thought.