Yea, the idea that individual workers somehow benefit in these types of situations if there's no union in place is weird.
The Worker Vs. Company conflicts that come up always favor a Company because they have more time, resources, and connections than an typical worker. The union's goal should always be to represent the needs of most workers most of the time, but there obviously will be situations where that puts an individual worker and their union at odds. This doesn't seem like a fatal flaw in the system any more than people will be elected to federal office who don't share your worldview.
Delta flight attendants aren't unionized (my step mother is one) and they are very anti union. They believe pretty strongly that they have a good relationship with management and do no need a union. From what I gather it's pretty unusual at least in the (US) airline industry.
The Worker Vs. Company conflicts that come up always favor a Company because they have more time, resources, and connections than an typical worker. The union's goal should always be to represent the needs of most workers most of the time, but there obviously will be situations where that puts an individual worker and their union at odds. This doesn't seem like a fatal flaw in the system any more than people will be elected to federal office who don't share your worldview.