useLabel concatenating label and aria-label

[dklymenk]

useLabel hook has this behaviour where if both label and aria-label are passed to it, both are eventually concatenated and exposed to the accessibility tree via aria-labelledby.

The relevant lines:

useLabel generates labelId and assigns it to ariaLabelledby.
https://github.com/adobe/react-spectrum/blob/main/packages/%40react-aria/label/src/useLabel.ts#L50

The object with ariaLabelledby is passed to useLabels.
https://github.com/adobe/react-spectrum/blob/main/packages/%40react-aria/label/src/useLabel.ts#L59-L63

Both element's id and ariaLabelledby are concatenated in useLabels.
https://github.com/adobe/react-spectrum/blob/main/packages/%40react-aria/utils/src/useLabels.ts#L31-L33

I also see that there are tests covering this exact behaviour.

So, I have no doubts that it was designed like this intentionally, but I wonder what is the actual use case behind it. The documentation for useLabel, useField or useTextField doesn't declare such interaction and it's not obvious why it would be the default.

I'm consuming @react-aria through @heroui/react. The component library passes label as both aria-label and label to useTextField, which then results in duplicated accessibility label like "Email Email". For example, here on their doc page:
https://www.heroui.com/docs/components/input#usage

@react-aria does similar label concatenations for selects #3821. In that case, I understand the value of such behaviour, but I can't understand what concatenation of label and aria-label accomplishes for useTextField.

Personally, I would expect label to be overridden by aria-label, at least if the standard accessible name calculation order was used as reference.

Anyway, I need someone to clarify and confirm that @react-aria does indeed behave as it should and it is the consumers that are not supposed to ever pass the same value as aria-label and label to useTextField. With that information, I'll be able to confidently work on a fix for this issue I encountered in the HeroUI itself.