I think it is a case of using a purposefully absurd metaphor because more straight forward ones are too obviously in conflict with basic immutable, toxic aspects of people's belief systems (drilled and blasted through in their childhoods) that function to labotomize their empathy for the hardships of others.

You know how like other cultures use fairy tales and myths to talk about taboos or impossible truths so does "western" culture use the absurd framework of spoons to talk about the "impossible" state of being incapable of what the ruling class demands of us daily.

From the wiki, the idea comes from an essay that somebody has written about a conversation they had with a friend about the struggles of chronic illness. The conversation took place at a restaurant, and she grabbed the spoons for use in a metaphor because there were spoons nearby. She gave her friend a set of spoons, and every time her friend mentioned doing a task, she took a spoon away.

It could have been anything, but spoons happened to be at hand and she wanted to make a physical representation of an abstract concept. The essay resonated with people, so spoons became entrenched. And now I hear people say that they're all out of spoons to express the idea that they've done all that they can that day.

I like to use D&D's concept of spell slots. Some activities are cantrips, I can do them every day no problem. Other activities may need a leveled spell slot, and depending on what else I need to do I might not have a spell slot available, or may need to use a higher level spell slot for a low-level activity.

Main difference is a long rest IRL doesn't always give me all my spell slots back.