Its employee choice. People get bored, they get tired of processes, and there are plenty of companies willing to hire them that will allow them to try something new, do something different, and deal with different processes.
You responded with an authoritative answer backed up with zero evidence or supporting data. That it was about unions is an embedded assumption based on that fact that the entire discussion is about unions.
I assume this is referring to the technological innovation and corporate profits of Silicon Valley. I would ask you to consider, from a broader perspective, what Silicon Valley is today. Specifically, in relation to elevated levels of depression [1], suicide [2] and inequality [3].
Isn't it worth exploring whether the same working conditions that benefit the top 10-20% are having a negative effect on the other 80-90%?
[1] https://money.cnn.com/mostly-human/silicon-valleys-secret/
[2] https://www.theatlantic.com/magazine/archive/2015/12/the-sil...
[3] https://fortune.com/2018/10/16/silicon-valleys-income-inequa...