I currently am mid 30s and 10 years into my career. I have no interest in joining a union right now, simply because I am confident in my skill and my ability to increase my earnings and career progression without being a member of a union.

Maybe when I hit peak earnings and no longer get a sizeable raise when hopping jobs every 3-4 years and the personal progression is no longer satisfying, I'd be interested in a union.

Notably, I have never been laid off and I have enough savings/investments to keep my family fed and housed for years if I am without work.

When I stop caring about career progression, about learning and growing, and just want to receive a paycheck for minimal effort until I can't be bothered showing up at work anymore, I'd be more than happy to join a union to ride it out. Until then, for purely selfish and individualistic reasons, I'd rather be solo.

Likely what would happen is by the time I want to join a union, it's no longer feasible for one reason or another, but I'll have enough savings by then (or we're all screwed anyway) to be fine.