I hope we all can agree that paying an organization a percentage of your salary or other form of dues to “have a voice” is a giant waste of money if that talk never translates into action. You shouldn’t need to pay someone for the privilege of voicing your opinions about your workplace - you can do that today for free, whether to your manager or to colleagues. There should be specific outcomes you are seeking when advocating for a union.

What are the actions you expect a union to be willing and able to take, that you cannot achieve without a union? How do these outcomes generate more value for members than the dues it takes achieve the outcomes? And to what extent can these outcomes be achieved with what would (likely) be a minority union?

These are some questions worth answering, imo.