The big tech companies are getting old. I think it's a fundamental rule that the competence and effectiveness of an org must fall, over time, driven by the fact that a person will more readily hire someone they can understand than someone that is more intelligent/competent/effective. This causes a slow degradation.
I also think there's been a drastic shift in the working culture of tech/engineering spaces, in general, over the last 15 years. From my experience, it's definitely drifted away from a bunch of nerds solving problems to something more towards emotional/personal/politics. I recently saw someone cry when a person very kindly asked them to explain a discrepancy. "Back in my day" people would just state facts, point out flaws, and argue a bit, and have fun doing it, for better or worse.
I also think there's been a drastic shift in the working culture of tech/engineering spaces, in general, over the last 15 years. From my experience, it's definitely drifted away from a bunch of nerds solving problems to something more towards emotional/personal/politics. I recently saw someone cry when a person very kindly asked them to explain a discrepancy. "Back in my day" people would just state facts, point out flaws, and argue a bit, and have fun doing it, for better or worse.