This - I can't think of any place I've ever worked where development ever outpaced backlog and tech debt.
Being overworked is sometimes better than being underworked. Sometimes the reserve is better. They both have challenges.
In that sort of high-fear, change-adverse environment "get rid of all the devs and let the AI do it" may not be the most compelling sales pitch to leadership. ("Use it to port the code faster so we can spend more time on the migration plan and manual testing" might have better luck.)