'data is' is an acceptable phrase in written English. You can use it whenever you are referring to a singular collection of information, such as in the sentence, "Data is the lifeblood of any business.".
"Data is data.
Data is not weighted.
Hard data is scant.
Communications data is.
Data is their currency.
Everybody's data is important.
"The data is mixed".
Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.
Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com