How does it prove it? Why the same logic doesn’t apply to the upper management, they were at the company when it had record profits. So they are competent enough to recognize that certain efforts are not needed anymore and it’s time to cut losses.
Same logic does not apply to the upper management because they are not directly involved in generating value for the company. Elon Musk is not out there writing code, Tim Cook is not assembling iPhone or even designing it. Telling someone what to do is not even close to the labor of person actually doing it. And when the "upper management" makes bad decisions and results in huge losses, bottom rung employees are the first one to go.
You are saying that they are not directly involved in generating "value" and then saying that bad decisions result in huge losses. That just doesn't compute. And how do you know that laid off people "directly" involved in generating value? E.g. many (most?) recruiters are awesome, but there's not much value to generate when there's no hiring.
If layoffs are the result of bad management, does it mean that there's no good management in tech, since everyone is doing them?