A field can look idle while it is doing work that does not resemble a harvest.

A resting field is not an idle one. Recovery, root growth, and the slow rebuilding of what the last crop took are all happening, and none of it looks like production from the gate. The absence of a visible yield is not the absence of work.

Apply this before judging your own fallow periods. Recovery from illness, the stretch after a loss, the year where nothing appeared to progress: these frequently produce the conditions everything afterwards depends on. Nobody can see it, including you. That is uncomfortable, and it is not evidence that the time is being wasted.