Based on that, the problem is a value add proposition. The really good coders might add more value as really good coders. Transitioning that person to a position of manager, might be negative value as there will be impact as a really good programmer will have to be replaced, and then trained to be a manager.
If you really want to transition to management from any previous role, go get outside training, add degrees or certifications to your resume. Apply for the next management position, or jump ship to a new company hiring in as a manager.
It can also give you some leverage in upcoming reviews after being passed over for management roles for a raise to make compensation on par as if you were doing a manager position. Where as if you are more valuable as a developer you should be compensated for the job you are doing, but don’t want to be doing.
I would also stress to, for anyone regardless of role to also negotiate for a severance package so that your cheaper to keep than to be let go. Start it low at a month or two of salary. Try for it lue of a next raise or a smaller raise plus severance when offered future raises. If you do get a severance package (in writing) make sure each future review you negotiate more months of pay in the severance. Also only accept the severance if it does not specify exit terms, so any exit from the organization you are compensated regardless.
Having it in months, then it is based on current rate pay on exit, so if you get significant future raises even more pain for them on exit.
Having severance protects you from all this, as you are now untouchable by the new manager.
When I worked in aerospace, there were various assertions about structural engineers getting into management over more specialized engineers because of their "whole vehicle" orientation or some such.
If you manage through stewardship, explain tasks and expectations, trust your report will make the right decisions. Then it’s mostly monitor allowing people good at their jobs to do their job. Then constant conversations individually, stand ups are great, but one on one as well every day.
I still find time to take ease to put down tasks. However most of my time is designing and grooming tasks, directing traffic, and unblocking my development team.
The job of a manager is to get out of the teams way, and to stay on top of roadblocks to keep all the lanes open. I also take responsiblity for watching out for process/workflow improvements to always keep improving, faster, better, less effort as that means more work done in less time and resource strain.