Unions do not help everyone. Unions often impose artificially high labor costs, which results in a lower amount of jobs being created. The real impact soon becomes apparent when companies start to lay off those union employees because their margins are slim and they try to automate as much as possible, instead of hiring people to do the job.
See the recent UPS layoff, just after 6 months of a great union deal: https://finance.yahoo.com/news/difficult-disappointing-ups-l...