So? Unions also bought and influenced media outlets. They also lobbied. It's not like unions just sat there while management poisoned the country's mind against unions.

Unions were not able to make a compelling case. They had every chance to do so, starting with them being the default option in many industries.

America abandoned unions for a reason. It may have taken a concerted effort by corporate capitalists to get there, but that's not why. "Why" is because more and more people felt that the unions were not a net positive for them.