Who has said that single people don’t have a mental load?
Everyone has a mental load of some sorts, what it entails differs. How is that difficult to understand? Why is the term such a bad thing when it says on the tin what it is?
You use your brain, your mind to think, see, observe, remember, and do a task.
Yes, the term is often used in reference to parents, particularly mothers, but nowhere in the definition does it say that only parents have a mental load.
Don’t like the term, fine, but it’s ridiculous to make it out as if it is an unnecessary term.
There’s plenty of terms about and some want to act as if synonyms aren’t a thing.
What do you want to call it?
Being an adult is vague because the age one is considered an adult varies widely, unfortunately as does what people consider being an adult.