[ryoshu]

You haven't been forced to join a union in the US - or pay dues if you don't join - since 2018 when the SCOTUS ruled against the practice (https://en.wikipedia.org/wiki/Janus_v._AFSCME). You could potentially start a competing union for, say, pipefitting, but the NLRB needs to approve it (federal agency). But now you are fighting management and a national union that already absorbed local ones over the last 150 years. Unions tend to consolidate over time because it gives more negotiating power for the members.

[syshum]

That is a misinterpretation of that ruling, which applies to non-union members being forced to pay dues

Union Shops, where by in Non-Right to work States the union negotiates with the Employer (private not public) that all employees of the group will be represented by the employer the employer can still be required to force employees to join the union with in 30 days, normally this is an automatic process for "union shops"

Again this varies by state, and Right to work states can not have such a provision, however Janus decision DID NOT outlaw union shops.

Also none of your comment seems to refute or attempt to explain the differences between UK or other EU unions and US unions, which is the context we are discussion, gotcha technicalities do not go to this over all conversation which is the vast differences between how unions operate in the US vs other nations.