My take on this is that: yes, a small minority of devs are substantially overpaid for their work right now. I don't think it will stop, since even if there is a glut of new developers, the ones with production experience at scale will always stand out from the fresh devs, and will be more prized for that reason.

What may end up happening is the funnel narrowing at entry, that is the salaries for brand new developers collapsing, while only a select few make it to the top. It reminds me of professional sports.