"Unions of type T are weak, therefore all Unions are without purpose" is not logical.

A poor implementation of a system is not a case against the system, particularly when other countries have proper implementations of the system.

(BTW I'm discussing things with the opinions given by others. I certainly don't think unions, even in the US, are particularly weak or useless. The president had to take action to prevent a particularly useful and impactful railworkers' strike last year. Teachers in Virginia got good pay raises after a strike several years ago. Writers and actors are fighting for their long-term survival against large studios.)