Your mistake is thinking a large corporation gives a single flying fuck about you as an individual employee (who's proven themselves rowdy by trying to bargain).
Every single time I put a notice in a large corporation, they tried to bargain with me to stop me from quitting, offering raises and improved working condition, eg. projects with more leadership roles. So no, they do care in some industries, especially when the cost of hiring a single worker is higher than Amazon warehouse workers entire yearly pay.
> mistake is thinking a large corporation gives a single flying fuck about you as an individual employee
You aren't negotiating against the corporation. You're negotiating against the people who determine your compensation. (This is a seemingly-minor, oft-overlooked and enormously-important distinction.)
Many on this forum have leverage over those people. (Some over the corporation.) For those people, unionization could be a net negative. Recognizing that doesn't mean the idea isn't worth pursuing.