The generalisation that the best instructors are the old silver haired foxes is too big in my opinion.
I totally agree with that. It is very often true, but it is very often not.
A freshly trained instructor can have no interest at all in instruction, or he/she can be super motivated to have landed their first actual job in aviation, and put a lot more effort in it than the student can reasonably expect.
A freshly trained instructor can lack important knowledge, or can have all that knowlege fresh in his mind from his own recent training.
An old fox can teach the student really important things that they would otherwise have missed, or he could overload the student with extra, unnecessary material that detracts from their ability to "just fly the airplane right!".
An old fox can teach tricks, methods and techniques that go beyond the basics and increase the student's abilities, or that are not up to the latest standards of aviation or instruction.
Just to take four randomly chosen specimens from an infinite list of examples.
Let's put to rest the fallacy that "experience makes you better", and rather realize that "experience
allows you to get better, iff you take that opportunity".