One can only leave and make it better elsewhere...
What makes you think the "old rot" wouldn't eventually overtake the new paradise? It will do precisely that unless the actual problems are recognized and remedies applied. Most of "school rot" comes from lawsuits levied by parents against the school:
Too much homework
My baby deserves better grades
Its the teacher's fault my child doesn't understand
It is OK for my child to be absent whenever he/she pleases
An infinite number of makeup tests should be allowed
It should be OK to makeup work months after it was due
The course is too hard
You must teach my slow child in the advanced classes
Why is that a required course? You should be able to handle a class and deal with disruption
So on, so on, so on.
You really don't understand the problems; therefore, you wouldn't be able to solve them. Changing locations simply won't help.
Changing the system by make small controllable environments that are parent run will make workable programs. Not school, programs, Because school as we know it is going away very soon.
I understand very well what you are talking about.
You cannot salvage it.
Remember Children are only in the system for a total of up to 12 years. They and their parents go away. The blob is there forever.
Leave it.
Totally.