The best way to unionize is to follow what Mahatma Gandhi did: Non-cooperation movement.

It consists of two broad strategies:

1. Consumer Non-Cooperation (Boycott): Boycott of stuff sold, or given by these companies, irrespective of how attractive it is.

2. The Constructive Program (Self-Reliance): Building and supporting alternatives, even if they cost you a little bit more.

All it needs is little self-discipline and a very very tiny bit of sacrifice on daily basis.

https://www.nextias.com/blog/non-cooperation-movement/

Massive individually coordinated group actions only work is very dire circumstances which means for most everyday things they cannot be relied upon.