I know that there are many former runners who get back to running after a long break and this subject probably keeps coming in discussion.
According to a recent study, muscles do not have memory. If you take a longer break, all work is gone.
However, the brain (and perhaps other anatomical elements) remembers how to build muscles and endurance.
So if you take a longer break, the brain won't have to learn again what's needed for endurance or muscle strength; it gets straight to work.
This is the article:
https://www.sciencenews.org/article/endurance-training-leaves-no-memory-muscles?tgt=nr