Canada

Perhaps increased job competition can motivate workers to unionise to defend wages and employment. On the other hand, a larger labour supply makes it easier for employers to replace uncooperative or striking workers, weakening bargaining power.

I personally see a large unemployment now as the Phillips curve inverted with high interest rates, and I now clearly see the wage suppression which erodes unions. But we can agree to disagree I guess.

I do think sometimes high skilled workers can increase productivity and increases per capita living standards, but we moved away from that under Trudeau to hide falling GDP, and to quell a wage price spiral that benefited workers and hurt asset holders who benefited from the asset price inflation of covid stimulus and QE. Productivity is what matters here though, which determines whether it helps rather than hurts existing laborers.