In the context of how not to be screwed over by an employer, and with the frequency and distribution of tech jobs in mind then yes, I believe that the number of situations where no alternative positions exists and the employer requires the complete sign over of all IP generated by the employee at all time to be so low it has no meaningful impact on the discussion.

And thus brings no value to such a discussion. That does not mean I dismiss the existence of such situations. I simply decide to see the whole forest, rather than focusing on a single tree.

And in case it had eluded you, we who work in the tech industry (which I would hazard a guess is the majority here on HN) are all privileged beyond what most of humanity has ever experienced in terms of job security and wages (even when taking into account the great big gab between the lowest and highest levels).