More generally unions can be one-sided in a sense. They try to make up for the lack of responsibility of corporations towards their workers, which is important

More generally unions can be one-sided in a sense. They try to make up for the lack of responsibility of corporations towards their workers, which is important (keeps them in check), but then there is the issue of bureaucratic bloat and power concentration within unions (organizers, lawyers etc.) so they can become detached from the actual workers and their trade. At the same time there are highly skilled workers with high work ethic who benefit less from unions than their peers. In my opinion a an ideal union is organized bottom up. Lawyers and organizers are there to support union workers and most importantly don't create a hierarchical structure where all negotiations happen at the top. Secondly a union should strive for the highest quality and work ethic among their workers. One should be proud to be part of one and have values and principles to strive for.