You should revist your stance on unions and start by reading up on how they work and what benefits they confer. Assuming you are not in the 1%, a union almost certianly would benefit you. It is a way of equalizing the playing field when the interests of BIG capital conflict with the quality of life and meaningful human experience of individuals.
I already have that agency. If I wanted money, I'd have long ago worked for a FAANG. I didn't because I wanted something else. I enjoy working at startups and small to medium sized firms for the challenge and flexibility in all matter of things I get to work on. I have shifted my career from being a sysadmin/netadmin, to devops, to development and it just involved getting involved at places I've worked at. There was no need for licensing, meeting requirements, etc.
If I felt I didn't have any of that agency, I'd likely feel differently about it. But I just don't see what any union (small or large) is going to do for me unless I was in a jurisdiction where they provided extra services like healthcare or other universal benefits.
The tech workers who are unionized that I know didn't join for financial gain because there is none (except for a few who are bad at bargaining). They joined to exert control over their workplaces and help build companies they can be proud of.