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.