In Australia collective bargaining workplaces unions negotiate the pay structure and benefits for all workers, members or not. This leads to some arguments that non union members benefit from the unions without paying the fees, and indeed, in my mostly white-collar government workplace only about 10% of workers are union members.
Unions mostly exist for unskilled workers (the most replacable) or specialised workers whose skills don't easily transfer elsewhere.
In the Netherlands employers pay part of the union contribution and members get some money from the union during the strike. Plenty of people are still not members
Unions mostly exist for unskilled workers (the most replacable) or specialised workers whose skills don't easily transfer elsewhere.