You're describing what Beverly J. Silver's "Forces of Labor" [1] refers to as "marketplace bargaining power," one of labor's "structural" (ie endemic) sources of political leverage.
> Marketplace bargaining power can take several forms including (1) the possession of scarce skills that are in demand by employers, (2) low levels of general unemployment, and (3) the ability ofworkers to pull out of the labor market entirely and survive on nonwage sources of income.
Marketplace bargaining power is valuable, but it's not perfect, safe, infallible, or free to exercise--especially if one is here on a precarious visa.
Additionally, as the tech job marketplace expands into the global economy, marketplace bargaining power approaches 0 (think: outsourcing).
> Labor's marketplace bargaining power has been undermined by the mobilization of a world-scale reserve army of labor, creating a global glut on labor markets. Moreover, to the extent that the global spread of capitalist agriculture and manufacturing is undermining nonwage sources of income and forcing more and more individuals into the proletariat, marketplace bargaining power is undermined further.
Tech workers are then left with other sources of structural bargaining power, which we had better not neglect: