Unions can cause industries/companies to stagnate if they make it too hard to fire people or if they squeeze their respective companies out of too much money.

Unions can cause industries/companies to stagnate if they make it too hard to fire people or if they squeeze their respective companies out of too much money. For union members pay, layoffs, etc. are often decided by seniority and not by ability or how hard you work. Whether or not that's worth it is up to you.