But that keep in mind you don’t have to keep progressing your career. There are risks to not doing so, but also rewards.
Since you mention "Outside of the top of the IC ladders at the giant tech companies" which is about $600k or thereabouts, I am guessing this means they are billing for about $500/hr-$600/hr? So a week's rate is roughly $20k+. What kind of place is paying software engineer contractors that much?
But there’s also the more classic knows-where-to-put-the-screw consultant. Something is broken and bleeding money and after being jerked around by underlings for a few weeks some director is desperate to fix it.
There’s are many many companies out there that can be losing tens of thousands of dollars a day or more because something isn’t working.
Next question is - is manager the only logical progression for a dev at some point?