One of the factors of burning out is a lack of control over the pipeline, that is over the contents, speed, and quality of what flows in and out.

So the weekend coding is an example of the opposite - having control over the choices, owning your time and inspiration.

Well, some degree of OCD likely is another factor in the burnout and the weekend coding just manifests this OCD.

Managing the high degree of complexity while being constrained by time by itself has a huge toll in the burning out.