You make some very good points but I would argue that many if not all the people you observe “without introspection” have enough to know they’re getting dummer but they don’t care because they never liked the art of writing code itself or problem solving they just liked getting a paycheck and are relieved that they can still have output their managers don’t fire them over with far less effort.

They see the same thing as you but are overjoyed to power down their brain and spend more time thinking about their personal hobbies and sports and 90 day fiance instead of real problem solving or code.