Indeed. You cannot release a patch for a mechanical part or a PCB.
Also common is to patch around issues, when possible, in firmware. This is often lower cost/effort, but can’t fix everything.
There are similar kinds of fixes for purely mechanical parts. Depending on the part and problem, mechanical can be easier than a PCB rework (eg: modify a part in CAD and 3D print or get your local machine shop to do a run).
I briefly looked at a couple used vehicles just outside of warranty and one within warranty that had literally had two oil changers in 100,000k, that’s 60,000 miles for the uninitiated.
> You cannot release a patch for a mechanical part
In NATO, this is frequent and normal. Many, many "recalls" are issued by military manfacturers, then local support staff spend X hours to replace the defective part. It is not so different from automobile recalls.It’s just a lot more expensive and labor intensive to apply.