> People don't want to leave a cushy job for one where they would have to work harder for their money, so instead, they are trying other means to have their cake and eat it too.
You're saying this like it's a bad thing. Why shouldn't employees expect, and get, better working conditions?
> engineers can "collectively bargain" with Google by simply leaving and working somewhere "better"
How is individuals leaving "collectively bargain", it's the complete opposite, it's individual bargaining, with all the perils that entails.
> Unions are intended for industries where a worker doesn't have a marketplace of options as there is a single or just a few employers (e.g. Hollywood, teachers, coal mining towns, hospital staff, etc.).
This is just a mis-conception, look at Germany where every industry has unions, regardless of size, and unions has a say in how companies are run, and what direction they head in. They make sure that shareholders and employees get input into the highest levels of leadership, ensuring that shareholders can't force decisions that benefit shareholders at the detriment of employees.
Finally Google looks like the perfect place for a union. Any company that rewards senior leadership for sexual harassment clearly doesn't consider it's employees important, and those employees should absolutely make it clear who generates most of the value in a company, and ensure they're treated fairly.