The official reason listed is to "promote our collective values: inclusion and solidarity, transparency and accountability; a seat at the table" and Kickstarter describes itself as a "Public-benefit corporation".
So it comes off as just the usual lefty political signalling, not the start of a real movement.
It's a ton of work to start a union, one that can and has absolutely cost people their jobs, both historically and recently. It seems unlikely that it's just "lefty political signalling". Perhaps you can point to specific reasons why you think this is the case?
Furthermore, articles published on this topic indicate that their motivations included well-established and reasonable on-call hours, slightly more vacation days, and more collaborative decision making with management. All of those are real, tangible benefits that most of us would value and enjoy.
So it comes off as just the usual lefty political signalling, not the start of a real movement.