> Nit picked, I suppose.

It's not a nitpick. There are some industries and jobs where employees truly are fungible. There's never going to be a security guard or Starbucks barista or janitor who does such an amazing job that they're able to negotiate significantly higher wages than their peers because of how much value they deliver. "Software developer" is not that kind of job, at least not right now.

> my overall point does not change that tech unions will depress wages for high earners.

And this goes back to the original point which is that unions only depress wages for high earners if the unions negotiate terms which depress wages for high earners. As has been pointed out in the thread there are many existing examples of unions for collections of high-earning employees.

You can believe that software unions will be like the actor and athlete ones but I will continue to believe that they are more like blue collar unions, with software unions in Europe as an example that currently exist. In other words, I have no reason to believe "unions negotiate terms which depress wages for high earners" will not be the case.