That depends, sure you can point to examples where the Union did improve peoples lives
But then i can also point to examples where they did not, where they ended up driving business out, bankrupting people
Where unions are more focused on their own political power than helping workers
Or even if in general the union helped the "average worker" the collectivist nature of unions means not everyone will be better off. For example Seniority, and "personal connections" are often more of a driving factor in Unions than merit or work performance. In fact highly efficient hard workers are often driven out of unions or forced to "work slower", etc.