C is like the old sawing machines. Hospitals saw a never ending stream of cut off fingers, and every recent model has safety features. Old timers claim you are a responsible adult human and should just watch out, and technically, they are correct. They hate he safety features which indeed make their job harder.
But it is humanly impossible to be 100% responsible at scale. You will have a bad day someday or be sick or whatever, and it will cost you a finger. In a team, 2 people will differ in what 'responsible' exactly means, and a dumb error will eat another finger and cause a lot of angry fingerpointing.
C is the same. A group of people, at scale, can't write good enough software all the time. Dumb tiny errors will sneak trough, and C will punish us with instability or security holes. If we want to build any trust in future software, if our profession wants to be engineers instead of hackers, we will require some safety features in our tools. Even if this costs us short term in some extra development time or runtime inefficiency.