The fight for unionization is great and all but it's one they must absolutely love: extremely slow, never likely to be won in a majority of workplaces. Basically a Horatio Alger story as far as the average wage laborer is concerned.
Are there any more practical means of pressing labor power?
For example, title. At hiring the employer makes you sign numerous contracts and agreements – they can also sign enforceable contracts, eg stipulating certain basic working conditions. They might decline to do so but… a small group with legal advisory could plausibly convince the vast majority of competent wage labor in my community to make such a contract with modest requirements a condition of hiring. That's at least a million times more plausible than seeing even just one local workplace unionize, and within just weeks new hires could start to see minor benefits.