> Unions are necessary because your employer is richer, stronger, and has more lawyers than you do as an individual. In unity there is strength.

To me this is the key point, that often gets lost or forgotten. Companies inherently benefit from a power imbalance, proportional to the size of the company, and you represent a cost center to them most of the time. This places you at a huge, and permanent, disadvantage, and one of the only ways to combat it is unify with other workers and bargain. The only person or group who exists to maximize your well-being is you/your union, not your employer, so it makes sense not to trust the employer to look out for you. They're busy maximizing returns for shareholders.