I know how Unions work. The OP stated: ...it's time for you to toss that leadership out. You can do that by leaving, or talking to management about this, or unionizing.

A Union can organize and sustain a strike. But they cannot "toss leadership out". Not the CEO, the Board or any manager at any level.

They could theorethically "blackmail" a company saying "strike will not end until X is fired" where X is a PM or manager or whatever but I never really heard of anyone trying this tactic, not to say actually succeed...