I am an individual who doesn't like just being one of a group, so I have never joined a union, but I support some union actions at my employer and so I too go on strike (and thus don't get paid) if I agree with the cause of their action. It can be simultaneously true that unions aren't perfect and that unionisation is better than not.

Indeed that's par for the course, there's plenty to dislike about democracy, but the alternatives we've tried are worse for example.